LinkedIn, the social network for professionals, is believed to be have been hacked and lost 6.5 million passwords, according to various reports.
The company, however, has yet to confirm the cyber attack but has said it is investigating the claim. Reports around the Web say 6.5 million passwords were posted to a Russian hacker site.
The passwords are encrypted and hashed, according to reports, but that hasn't made them unbreakable.
Among the stolen passwords, 300,000 are believed to have been cracked, according to The Next Web. And one cyber security expert has reportedly said LinkedIn's attacker has requested help cracking the passwords.
And one user tweeted that his password was among those stolen.
LinkedIn has 150 million users, and it is a publicly traded company. The company responded to a request for comment by saying the best thing to do is to follow LinkedIn's twitter.