高考英语阅读训练（089）
It began as a game: high school and college students studying computer technology figured out (领会到，想象出来) they could use personal computers to break into (闯入) telephone company computers and make free, long-distance telephone calls. These young computer wizards (奇才) soon gained the nickname "hackers (黑客)".
Police put the collar on (拘留，逮捕) a few hackers, but many went on to even more complex hacking. One hacker was arrested for making illegal telephone calls and later used a jailhouse (监狱) phone to alter (变更) a police officer's credit records (信用记录) to get back at (报复) the officer for arresting him. The hacker also used a computer to alter his college records to give himself better grades.
As hackers gained experience, they began invading (侵入) computers at banks, airlines and other businesses. In one scheme (计划，方案), a hacker instructed an airline's computer to give him free airplane tickets.
The U.S. government is worried hackers may break into its sophisticated (复杂的，尖端的) networks of defense computers. The government's classified (分类的) secrets are vulnerable (脆弱的) because thousands of government computers are connected by telephone lines that hackers can tap into (敲入，进入).
In November 1988, a college student tapped into a non-classified U.S. Defense Department computer network called Arpanet. The hacker injected (输入，注入) a computer program that left copies of itself throughout Arpanet. Some hackers use each "viruses (病毒)" to destroy all the data in a computer. But in this case, government officials shut down the network before the program reached every computer in the system. Shutting down the system angered many researchers who were using the computers. The hacker turned himself in (自首) to police and told them how to get his program out of the computer system. He was c