Last updated: 3/27/2000
Link back to course Welcome

What was covered in class on April 6:
In class on April 6, we covered the agneda Items I through VI, and all of the handout "Using MS Access"

Computers, the Internet, and Society
Agenda for Class 7
4/6/2000

1. Announcements
   1. Online grade reports are working - see me if you need to be reminded of your password for this system
   2. Do sign-in.
   3. Handouts to bring every week
      1. Windows Common Elements
      2. Internet
      3. Forms of Computer Information
      4. Using WS_FTP
   4. Essay 1 was due a while ago. Only two have been turned in (counting Donna).
   5. Essay 2: This essay should have the same length and form as Essay 1 (five pages with header, title, introduction, body and conclusion). For the topic, pick either The Lexus and the Olive Tree or Release 2.1, and choose any two of the topics from the Internet Issues handout. Integrate these two topics into a single subject for your essay, using material from the book you chose. Be sure to tell me in the header at the beginning of your essay, which book and which topics you are writing on.
2. Internet News Stories
   1. US District Court judge Thomas Penfield Jackson issued findings of law in the Microsoft antitrust case, findings that largely upheld the Justice Department suit against Microsoft. Microsoft announced that it would appeal. It is expected to be at least two years before the appeals run their course. The next phase of the trial will be the penalty phase. The main points of Jackson's findings were that
      1. Microsoft used anti-competitive methods to sustain its monopoly for PC operating system software
      2. Microsoft tried to form a monopoly in web browsers
      3. Microsoft illegally tied its Internet Explorer web browser to the Windows operating system
      4. Microsoft did not make it impossible for Netscape to distribute its Navigator web browser
         Some comments:
         1. Microsoft's announced purpose in making Internet Explorer part of Windows was to make Internet resources (e.g. URLs, which represent files) available with the same methods as local resources (e.g. files, using Windows Explorer). I feel that this would simplify Internet access for most people. Microsoft may, however, have gone about this laudable purpose in an illegal manner. Still, I would not want to see this goal made illegal. (Some complaints have been made that Microsoft adds too many things to Windows.)
         2. Microsoft's competitors at the time when it was developing Windows, for example Word Perfect and Lotus 1-2-3 (spreadsheet) were slow to appreciate the significance of Windows and issue Windows versions. They did have warning - the early versions of Windows were pretty bad, but showed rapid improvement. Adding printing, for example, to the Operating System, was a big improvement and simplification for users.
   2. Cisco Systems, the top supplier of Internet routing equipment, announced that it will start selling corporate telephone systems based on the Internet. Telephones would transmit audio using the Internet, and each telephone would be an IP address. If an employee moved from Boston to London, the employee's telephone would plug in and be ready for calls immediately, using the old telephone number. (New York Times, Pg C4, 3/27/00)
   3. LaGrange, Georgia, about 60 miles north of Atlanta, announced plans to become the nation's largest 100% online town. The city will spend about $300,000 to connect the last citizens to cable, supply TV set-top boxes (cable modems?), provide Internet access devices for those without PCs, and send technicians into homes to explain the technology. Why LaGrange? It already has many corporate headquarters, and want to make sure that its citizens have the skills to maintain this advantage. (New York Times, Pg C4, 3/27/00)
   4. Blind and deaf people will be better able to enjoy movies with new technology. The "Rear Window" system will display subtitles on a large panel at the rear of the theater, and patrons will hold up partially transparent reflectors to see both the movie and the subtitles. The "DVS Theatrical" system will send a second audio channel describing the on-screen action through special headphones. (New York Times, Pg C13, 3/27/00)
   5. The "Yahoo Internet Life Online Film Festival", a two-day festival held last week, showcased digital cinema. Studio-quality digital recording and editing equipment is now available at 10% of the cost or less of the equivalent film-based equipment. Do-it-yourself movies are now growing quickly, with do-it-yourself or specialized web distribution sites. Some web distribution sites (not all are in current operation) are
      1. www.atomfilms.com
      2. www.eveo.com
      3. www.popfest.com (companion web site to to the online festival)
   6. IBM announced an improvement in making computer chips. The improvement is in incorporating an improved insulator that reduces cross-talk between wires. Since cross-talk increases with clock speed, this will result in higher clock speeds.
   7. Government officials warned that identity theft - primarily theft of Social Security Numbers, but also names, addresses and credit card numbers  - has increased sharply, due primarily to the ease and speed of Internet communications. Officials said that this was not a warning to stop using the Internet, but that "all of this enthusiasm should be tempered with a little bit of caution." Credit card fraud does not result in large consumer losses, since the banks issuing the cards usually get stuck with the losses. However, the trauma and inconvenience are still significant. Some web sites (www.docusearch.com and Net Detective at ndet.collector-club.com?sid=detton) promise to help you locate information about others. Some precautions and responses to identity theft are:
      1. Check your credit reports at least annually.
         1. Equifax 800-525-6285
         2. Trans Union 800-680-7289
         3. Experian 800-301-7195
      2. If you suspect identity theft, call the Fraud Hotline at the Social Security Administration (800-269-0271) or the ID Theft Hotline at the Federal Trade Commission (877-438-4338)
      3. If you become a victim of identity theft,
         1. Contact the credit bureaus above and ask that a fraud alert be placed in your file
         2. Contact your creditors and alert them
         3. File a police report and keep a copy available as proof for working with creditors
3. Student Evaluation of Teaching (SET)
4. Finishing up
   1. From the Assignment Schedule: I will allow you to redo assignments and turn in missing work after the course is over. Such work will not appear in your regular grade, but it will be taken into account in a Change of Grade, and it will eventually appear on your official transcript. The University will allow me to file a Change of Grade up to one calendar year after the end of the semester in which you took the course. For this course, that is through the end of the Winterl 2001 semester. I will not accept major assignments during the last month of this period. If you are redoing an assignment, the original assignment with my comments and grades must be turned in along with the redone assignment.
   2. To count in the regular course grade, work must be in by the day of the Final Exam, April 27. Work turned in after that will show up in a Change of Grade.
5. Antivirus protection
   1. Viruses
      1. What is a virus? A computer virus is a program that saves itself as a file on your computer and/or changes existing files. The end result is that almost anything bad can happen, depending on the type of virus. There are tens of thousands of known viruses that can delete files, change file extensions, cause your other programs to malfunction, and always try to get into other computers. Viruses spread via floppy diskettes and other portable disks, and via modem and network and Internet connections.
         
         Originally viruses were standard executable programs but with the advent of Microsoft's widespread and powerful scripting languages for Word and Excel, macro viruses have become common. (Access also is vulnerable, but it is not used often enough to attract virus developers.) Application scripting languages are not as powerful as regular programming languages, so macro viruses have so far not done as much damage.
      2. Until recently, email messages could not carry active viruses. Viruses can be contained as *.exe or .com in attachments, but the attachment has to be extracted and then activated before the virus can work its evil. But Microsoft Outlook has a scripting language that can be inserted in a message, and executed by simply opening the message to read it.
         
         Also, web pages now have scripting languages such as Java, JavaScript and VB Script. (VB script is not popular enough to attract virus developers.) These scripts run automatically when the page is viewed. Since it was recognized very early that this presented a danger, web scripting languages are generally only enabled for working within the Browser window. Microsoft's ActiveX controls are exceptions; their language is quite powerful. Microsoft has a program of certifying ActiveX controls as being legitimate, and this prevents uncertified controls from executing.
      3. What motivates people to develop viruses? Eastern Europe has many highly educated but underemployed computer programmers, who see their Western colleagues as rich and spoiled. Many viruses come from this region. Some viruses are more or less innocent experiments that get out of control. But most viruses are written to demonstrate the user's superiority over the common user, or the careless server administrator. Ultimately, the motivation of the virus developer is irrelevant. The user must protect him/herself.
         
         I can promise you that getting infected by a computer virus will/make you be good and protect yourself, at least for a year or two. But highly effective and easy to use protection is widely today, so there are few excuses. The best protection is a good anti-virus program that is updated regularly, and starting with other methods is not meant to steer anyone away from that. Here are some methods for protecting your computer.
         1. Be careful about whom you accept files from. Commercial "shrink wrapped" software is supposed to be very safe. Safety goes downhill from there.
         2. Watch for unusual operation after loading a new program on your computer.
         3. Applications with scripting languages should have settings for which you are warned before a macro can run. Make sure that these settings are enabled. Do not let the macro run if you have reason to doubt the source.
         4. The big one. Buy a virus program. The common ones are all excellent; Mcafee, Symantec (Norton) and IBM. As each new generation of viruses comes along, the programs must be rewritten, most recently to check email macros, so don't find an old program and recycle it. Plan on buying a new anti-virus program every year or tow. If you see "shield" in the name, that means that the program will put a virtual shield around your computer, and scan all files that you open, whether on a floppy or a network. And in addition, it should prompt you to scan all existing files regularly. Modern anti-virus programs also automate regular updating of the virus definition files, and free updating should come with the product. The program should prompt you regularly, say every two weeks, to check its home site for updates. The updates should be downloaded and installed automatically. When your anti-virus program tells you that it is time to update, let it do its thing.
      4. Recently, with the Babylonia virus, it has been demonstrated that Windows help files (extension .hlp) can also contain a virus. The following types of files can contain viruses:
         1. .exe
         2. .com
         3. .dll
         4. .doc, .dot (Word)
         5. .xl* (Excel)
         6. .mdb (Access)
         7. .hlp (Windows help)
      5. One additional point: corporate computers are extensively connected by LANs, and therefore make it easier for viruses to spread. Virus writers know this, and most viruses are found on corporate computers. Viruses on home computers are less common, but on the other hand, home computers do not have the extensive technical support, so viruses are harder to repair.
   2. Virus hoaxes are false warnings about computer viruses. Why do this? Creating a good virus can be difficult and can land you in jail. Creating a virus hoax is easy, and you probably would not go to jail if caught. And you can write a good scary email and sit back and watch it spread. Many virus hoax messages simply make small changes in a previous hoax and resend. I have gotten several virus hoax notices in these classes; hence this topic. A virus that destroys its host computer, or deletes all the files on its hard drive, cannot spread itself after it does that. Any notice of a virus that will destroy all of the files, destroy the computer, or something like that, is probably a hoax. A favorite phrase is that IBM, or AOL, or IBM and AOL, have verified that this hoax does all of those terrible things.
   3. To check out notices of viruses and hoaxes, I like the following web sites:
      http://www.av.ibm.com/BreakingNews/VirusAlert/
      http://www.av.ibm.com/BreakingNews/HypeAlert/
      http://www.mcafee.com/centers/anti-virus/default2.asp
      http://vil.mcafee.com/hoax.asp
      Network Associates (McAfee) http://vil.nai.com/villib/alpha.asp
      Computer Incident Advisory Capability (CIAC - US Department of Energy antivirus site) http://ciac.llnl.gov (find other anti-virus links here)
      CIAC Virus Hoax page http://ciac.llnl.gov/ciac/CIACHoaxes.html
   4. From Agenda 4: Protecting yourself from being taken over for Denial of Service attacks. An article in the New York Times' "Circuits" section today (2/17/2000, Pg D1) gave suggestions about how to protect your home computer from Internet-based attacks, or being coopted in a DDoS attack.
      1. A free Internet site, www.grc.com, called ShieldsUP! will scan your home computer for Internet vulnerabilities in the way that a hacker would, and tell you about them. The site also has a tutorial on Internet security.
      2. Internet vulnerabilities can be exploited to place computer files on your computer. The first line of defense, according to the article, is a good antivirus program with "Shield" capability and up-to-date virus definition files.
      3. The article lists several programs that you can run on your computer to set up a firewall that inspects all Internet traffic coming into your computer, and blocks unauthorized packets. More of these programs are expected on the market soon, but here are some available now:
         1. BlackIce Defender, $40 from Network Ice at www.networkice.com
         2. Norton Internet Security 2000, $55 from Symantec at www.symantec.com
         3. (Recommended by reviewer) ZoneAlaram 2.0, free download from www.zonelabs.com. Pops up an alarm if your system is being scanned for vulnerabilities. Also monitors your running programs to see which ones - legitimately or otherwise - are trying to send information back out to the Internet.
   5. Spam is bulk email, like junk mail, usually for advertising purposes. At its worst, Spam can overload a user's mailbox, making email unusable. Spammers are both amateur and professional.
      1. Spammers get addresses from UseNet news groups, and by scanning web pages with "mailto" links in them. Lists are posted to the Internet and exchanged.
      2. One line of defense is to look at the email headers to find out where the mail came fromand how it was passed. Directions for doing this vary widely among email programs. Consult http://digital.net/~gandalf/spamfaq.html for hints. Here is a sample set of headers:
         
         Received: from post.info.drugstore.com (post.info.drugstore.com [216.32.6.82])
         by mail1.wayne.edu (8.8.5/8.8.5) with ESMTP id KAA05623 for
         <d.r.bowen@wayne.edu>; Tue, 14 Mar 2000 10:37:06 -0500 (EST)
         Message-ID:
         <200003141537.KAA05623@mail1.wayne.edu>
         Received: from PickupDirectory by post.info.drugstore.com with SMTP
         (Microsoft Exchange Internet Mail Service Version 5.5.2448.0) id
         19TQ02D9; Tue, 14 Mar 2000 07:33:39 -0800
         From: "drugstore.com" <drugstore.com_000268@info.drugstore.com>
         To: <d.r.bowen@mail1.wayne.edu>
         Subject: Save the planet with great natural products
         Date: Tue, 14 Mar 2000 04:13:20 -0800
         MIME-Version: 1.0
         Content-Type: multipart/alternative;
         boundary="----=_NextPart_000_1DD030_01BF8D6B.A1E66030"
         X-Recipient_Key: 162568
         X-Cq_Job: 268
         X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3612.1700
         
         The goal is to pick out the address of the spammer's Internet Service Provider. Then email that ISP and complain. Since spammers are universally reviled, many ISPs will discipline clients who are spammers.
      3. There is software to filter out Spam, both at the user level and the ISP level (incoming and outgoing). Yous ISP may install this if you are victimized. Here is a list from Yahoo
         1. Anti-Spam Provisions in Sendmail
         2. BlackMail Anti Spam Mailer Daemon - a highly configurable SMTP mail filter that runs at a system level as a proxy to your existing mailer.
         3. Fight Junk Mail - two packages to help combat internet spam.
         4. Infinite Ink's Mail Filtering and Robots
         5. jmfilter
         6. junkfilter - a procmail-based junk email filter system. Filter junk from Cyber Promotions, Nancynet, Quantcom, and many more. End junkmail with falsified headers. Filter it!
         7. makebait - how to make your own bot bait.
         8. NewApps.com Anti-Spam Tools
         9. Procmail Filters Kit
         10. RBL Code
         11. S.C.S. Spam Mail Filter for NT - freeware for users of EMWAC's Internet Mail Software.
         12. Sam Spade - web interface to many network tools, including traceroute, dig, whois, secure web browser, URL decipherer.
         13. Spam Hater - free Windows software that helps you to hit back at the spammers.
         14. Spambam
         15. Spambot - stops robots from collecting you email from a web page.
         16. Spambot Beware - Help on how to hide your email address on web pages. Also shows ways to detect and harass spambots.
         17. Spammer Slammer
         18. Using check_* in sendmail 8.8 - rulesets for validating RCPT, MAIL, check_compat, etc.

   Most email clients will also filter out unwanted email. Here is an example of a filter dialog, from Netscape Communicator:
   
   This dialog defines a single filter; multiple filters can be combined. Other email programs will do this slightly differently, of course. Another example is shown in How the Internet Works.

6. Databases - go to Access handout
7. Finishing off the forms of computer information
8. Windows common elements - go to handout

9. Update on web pages
   1. Browser cache
      1. Cache = local special storage, in this case, for web pages you have visited
      2. Maintained by web browser, separate sections on hard drive and in working memory
      3. When Browser requests a file from server, by means of a header, it asks the Browser to return the current date of the file. If the date of the file in the cache is the same as the date of the file on the server, the Browser provides a faster response and reduces the load on the server by displaying the copy in the cache. Normally this works pretty well, but the date comparison (apparently) does not include time. So if you view a page from the server in the morning and change it on the server in the afternoon, and then view it the same day, your Browser will still display the older cache copy.
      4. There are solutions. Each Browser has a method for overriding the cache and forcing an update from the web server.
         1. Netscape - <Shift>Reload
         2. Internet Explorer - Reload or <F5>
         3. You can also clear the cache in both Browsers to force going tot he server. Be sure to clear both the disk and RAM cache.
         4. If you normally work on a quickly-changing web site, you might consider zeroing the memory devoted to cache storage. Again, be sure to zero both the disk and RAM cache.
   2. How the web handles different file types
      1. When the web server receives a URL specifying a certain file, for most file types in most folders, the web server simply returns the file to the Browser, letting the Browser figure out how to handle it. Exceptions: executable files (*.exe) in specified directories (e.g. cgi-bin, cgi-win) are executed on the server with an output file returned to the Browser. "Server-side script files" (e.g. Perl, *.pl) in any folder are also executed on the server with an output file returned to the Browser. These are the mechanism for "interactivity" - taking input from the user via a form, processing that information on the server, and returning a customized file to the Browser.
      2. Web Browsers handle certain file types internally. These types are HTML, GIF, JPEG, PNG and a few other minor types. All of these "automatic" types are displayed on the screen by the Browser.
      3. For many other file types, the Browser may have been configured to use "plug-in" or "helper" applications to handle the file type. Many of these applications are proprietary, and may even be pre-configured in the Browser. Usually the Browser plug-in can be downloaded for free, as a means to building traffic and therefore sales for the server-side software. Examples:
         1. *.pdf (portable document format). Use Adobe Acrobat Reader to display the file on the screen.
         2. *.rpm. Use RealPlayer for this multimedia (sound, graphics and video) file.
         3. *.mov. Use QuickTime movie player
         4. *.wav. Use Windows sound player
      4. Many desktop applications will, by default, install themselves as viewers for their file types. Examples are Word (*.doc), Excel (*.xls), Access (*.mdb) and PowerPoint (*.ppt). When one of these file types is returned, the Browser starts the corresponding application to display the file. These files are not displayed in-line in the Browser window, but as separate windows. There may be a choice between saving to disk and displaying the file.
      5. The Browser can also be configured to execute scripts (e.g. javascript, java, vbscript) embedded within an HTML file.
      6. If the file type is not one of 2, 3, 4, 5 or 6, then the Browser will ask the user what to do with the file. The normal option is to save it to disk for later offline processing.
10. Forms of computer information - finishing this handout
11. Windows Common elements - finishing this handout
12. Internet - finishing this handout
13. WS_FTP - handout