Encyclopedia of Computer Science and Technology

speech recognition and synthesis 451that does not include Spam (the popular luncheon meat). Agroup of Vikings then keeps interrupting the conversationby loudly singing “Spam, lovely Spam, wonderful Spam. . . .”Segue to the mid-1990s when people (including a legal firm)began automatically posting hundreds of identical messageson Usenet (see netnews and newsgroups) groups; thesketch came to mind and the postings were quickly dubbed“spam”—although the term may actually date back to the1980s. As news of the spam grew, some administrators andusers used “cancelbots” to automatically delete the offendingmessages; others opposed this as censorship, and manynewsgroups became effectively unreadable.While spam can appear in any communications medium(including chat, instant messaging, and even blogs), themost prevalent type is e-mail spam, which costs U.S. businessesbillions of dollars a year in processing expenditures,lost time, and damage caused by malicious software (malware)for which spam can be either a delivery vehicle or aninducement. In 2007 an estimated 90 billion spam messageswere sent each day.The fundamental driving force of spam is the fact that,given one has Internet access, sending e-mail costs essentiallynothing, no matter how many messages are sent. Thuseven if only a tiny number of people respond to a spamsolicitation (such as for sexual-enhancement products), theresult is almost pure profit for the spammer.Besides directly making fraudulent solicitations forproducts that are ineffective, counterfeit, or nonexistent,spam carries two other dangers: inducements to click tovisit fake Web sites (see phishing and spoofing) andattachments containing viruses or other dangerous software(see computer virus and spyware and adware).Fighting SpamMuch spam is spread by first compromising thousands ofsystems (via viruses) and planting in them “bots,” or softwarethat can be programmed to mail spam. The controllersof “botnets” can then sell their service to spammerswho want to get their message distributed widely. Thespammers can also buy lists of e-mail addresses that havebeen “harvested” from postings, poorly secured Web sites,and so on.Ways to stop the spread of spam include the following:• e-mail filtering software, using a combination of textanalysis by keyword or statistical correlation (seeBayesian analysis) and lists of Internet locations(domains) associated with spamming; filtering can bedone both by service providers and individual users,or collaboratively• tightening the technical requirements for messages tobe accepted by mail servers (much spam has poorlyformatted headers)• improving techniques for blocking the viruses usedby spammers to set up their bots—see computervirus and firewall• attempting to shut down the infrastructure that supportsspam operations, such as hosts who allow bulke-mail, and sellers of spamming software and illicitlygathered address listsSpam is illegal in a number of respects. Spamming is againstthe “acceptable use policy” of most Internet Service Providers(ISP), though willingness to enforce these rules varies.In 2003 Congress passed the CAN-SPAM act, whichbans bulk e-mail that contains misleading subject or headerlines, but has been criticized for being weak and for preemptingmore stringent state laws. (The law also requiresthat messages include an opt-out provision, but spammerssimply use this to verify that the e-mail address is valid.)Although filtering software and other measures canreduce the amount of spam seen by the average user, spammersand spam-fighters continue their relentless battle witheach countermeasure, leading to altering the spam to makeit more likely to pass through. In the long run probablyonly a Net-wide authentication of all e-mail senders and/ora small per-message e-mail fee could effectively banish thescourge of spam.Further ReadingBoutin, Paul. “Can E-mail Be Saved?” InfoWorld, April 16, 2004.Available online. URL: http://www.infoworld.com/article/04/04/16/16FEfuturemail_1.html. Accessed November 18, 2007.Garretson, Cara. “12 Spam Research Projects That Might Make aDifference.” Network World, November 2007. Available online.URL: http://www.networkworld.com/news/2007/112007-spamresearch.html.Accessed April 28, 2008.Gregory, Peter H., and Michael A. Simon. Blocking Spam & Spywarefor Dummies. Hoboken, N.J.: Wiley, 2005.Lee, Nicole. “How to Fight Those Surging Splogs” [spam blogs].Wired News, October 27, 2005. Available online. URL: http://www.wired.com/culture/lifestyle/news/2005/10/69380.Accessed November 18, 2007.Markoff, John. “Attack of the Zombie Computers Is a GrowingThreat.” New York Times, January 7, 2007. Available online.URL: http://www.nytimes.com/2007/01/07/technology/07net.html. Accessed November 18, 2007.McWilliams, Brian S. Spam Kings: The Real Story behind the High-Rolling Hucksters Pushing Porn, Pills, and %*@)# Enlargements.Sebastapol, Calif.: O’Reilly, 2004.Naughton, Philippe. “Arrest of ‘Spam King’ No Relief for Inboxes.”Times (London) online, June 1, 2007. Available online. URL:http://technology.timesonline.co.uk/tol/news/tech_and_web/article1870548.ece. Accessed November 18, 2007.Spammer-X. Inside the Spam Cartel: Trade Secrets from the DarkSide. Rockland, Mass.: Syngress, 2004.Zeller, Tom. “The Fight Against V1@gra (and Other Spam).” NewYork Times, May 21, 2006. Available online. URL: http://www.nytimes.com/2006/05/21/business/yourmoney/21spam.html?_r=1&oref=slogin. Accessed November 18, 2007.speech recognition and synthesisThe possibility that computers could use spoken languageentered popular culture with Hal 2001, the self-aware talkingcomputer in the film 2001: A Space Odyssey. On a practicallevel, the ability of users to communicate using speechrather than a keyboard would bring many advantages, suchas mobile, hands-free computing and greater independencefor disabled persons. Considerable progress has been madein this technology since Hal “talked” in 1968.