( WIRED ) -- It 's one of the biggest data breaches in history . Now that Sony has come clean -- sort of -- on a computer intrusion this month that exposed personal information on 77 million PlayStation Network users , one obvious question remains : Who pulled off the hack ? In the old days , the answer would be simple : some kid did it . But today 's underground is more complicated -- a slew of competing players with different agendas and techniques . Here 's a quick rundown on the likely suspects . Anonymous . While noncriminal pranks are their stock in trade , the griefers of Anonymous have been on a hacktivism spree of late , staging distributed denial-of-service attacks against the corporate enemies of WikiLeaks , then famously cracking the computer security firm HBGary Federal and exposing the shady plotting of its CEO . Coincidentally , Anonymous declared Sony as its latest protest target right around the time of the intrusion . They were unhappy with Sony 's lawsuit against PlayStation 3 rooter George Hotz , and unsatisfied by the settlement deal reached between Hotz and the company this month . But spokespeople for Anonymous have denied any role in the PlayStation Network hack , and the whole flavor of the hack just is n't Anonymous ' style : they 've pulled intrusions in the past , but computer crime is n't their mainstay , and a stealth run through the network of a corporate giant is decidedly short on lulz . Verdict : Probably innocent . WIRED.com : Sony to inspect PlayStation hacker 's hard drive . China . Chinese hackers have been responsible for some of the most sophisticated known intrusions in recent years -- low-and-slow attacks against defense contractors , human rights groups and Silicon Valley bigwigs like Google . The attackers typically get in by hitting a single employee with an exploit , and then carefully expand through the network until they 've found what they 're looking for -- generally trade secrets , source code , or intelligence . A list of 77 million names , dates of birth and passwords could be useful as the raw material for future attacks , but aside from that , Sony 's gaming infrastructure is not a logical target for this bunch . You also would n't expect a professional Chinese intrusion to be detected so quickly . Verdict : Innocent . Random recreational hacker . This breed still exists , though now in much smaller numbers than the professionals . The PlayStation Network would be an alluring target for a bored teenager or twenty-something who spends a lot of time grinding through multiplayer shooters -- to paraphrase `` Silence of the Lambs , '' you covet what you see every day . A recreational hacker might go after the user database as a trophy . Verdict : Maybe guilty . WIRED.com : Sony claims PlayStation 3 hacker sabotaged hard drive , skipped town . For-profit cyberthief . These guys , largely concentrated in Ukraine and Russia , know databases like the backs of their hands -- they dream in SQL -- and similar , if smaller , stolen databases are bought and sold routinely over carder forums and in private transactions . In this scenario , the credit card numbers potentially stolen in the hack are n't as important as they seem . According to Sony , the CVV2 -- the security code on the back of card -- was n't stored in the compromised database , which greatly reduces the cards ' usability to fraudsters . Credit cards without the magstripe data or CVV2 are among the least valuable commodities . But combined with the other data , the database is valuable indeed . The passwords ( which Sony evidently did n't bother to hash ) could be a gold mine , because people have a tendency to use the same password everywhere ; you can bet a big chunk of those 77 million PlayStation Network passwords will unlock everything from Facebook accounts to online banking . The e-mail addresses could be used in phishing attacks , with the fraudster using stolen details -- like the target 's date-of-birth -- to increase the chances of a response . Hell , even if it were just sold as a spam list , the Sony database could draw a pretty penny . Verdict : Probably guilty . Subscribe to WIRED magazine for less than $ 1 an issue and get a FREE GIFT ! Click here ! Copyright 2011 Wired.com .
Personal information on 77 million PlayStation Network users was exposed recently . Here 's the run-down of who might have done it . A for-profit cyber-thief probably did the job .