Itbeganasagame:highschoolandcollegestudentsstudyingcomputertechnologyfiguredouttheycouldusepersonalcomputerstobreakintotelephonecompanycomputersandmakefreelong-distancetelephonecalls.Theseyoungcomputergiftssoongainedthenickname"hackers（黑客）".

Policearrestedafewhackersbutmanywentontoevenmorecomplexhacking.Onehackerwasarrestedformakingillegaltelephonecallsandlaterusedaprisonphonetochangeapoliceofficer'screditrecordstogetbackat（报复）theofficerforarrestinghim.Thehackeralsousedacomputertochangehiscollegerecordstogivehimselfbettergrades.

Ashackersgainedexperiencetheybeganinvadingcomputersatbanksairlinesandotherbusinesses.Inoneplanahackerinstructedanairline'scomputertogivehimfreeairplanetickets.

TheU.S.governmentisworriedhackersmaybreakintoitscomplexnetworksofdefensecomputers.Thegovernment'sclassifiedsecretsarevulnerable（脆弱的）becausethousandsofgovernmentcomputersareconnectedbytelephonelinesthathackerscantapinto.

InNovember1988acollegestudenttappedintoanon-classifiedU.S.DefenseDepartmentcomputernetworkcalledArpanet.Thehackerinjected（输入，注入）acomputerprogramthatleftcopiesofitselfthroughoutArpanet.Somehackersuseeach"virus"todestroyallthedatainacomputer.Butinthiscasegovernmentofficialsshutdownthenetworkbeforetheprogramreachedeverycomputerinthesystem.Shuttingdownthesystemangeredmanyresearcherswhowereusingthecomputers.Thehackerturnedhimselfin（自首）topoliceandtoldthemhowtogethisprogramoutofthecomputersystem.Hewaschargedwithacrime.

TheincidentattractedcomputerhackingintheUnitedStates.Manycompanieshavehiredexpertstoprotecttheircomputersfromhackersandmanycomputerexpertsnowadvisecompaniesonhowtoprotecttheircomputers.

TheU.S.governmentbelievesforeigngovernmentshavehiredhackerstotrytobreakintotop-secretdefensecomputers.Itfearsahackercouldinjectavirusintomilitarycomputersthatwouldcleanupallthedataduringawar.

Expertsdisagreeoverwhetheracomputernetworkcaneverbesafefromhacking.ButinthefuturesomeofthemostbrilliantmindsintheU.S.will