'Facebook' is the largest social networking site in the world with more than 800 million members who spend more than a total of 700 billion minutes on the site per month.
Out of more than a billion logins to the website every 24 hours, 600,000 are impostors attempting to access users' messages, photos and other personal information, according to 'Facebook'.
The figure was revealed as part of a 'Facebook' blog post announcing a couple of new security measures being implemented across the site over the coming weeks to tackle these sorts of breaches, 'The Daily Telegraph' reported.
Security experts have said the figure is a "big concern" and that people need to be more careful when choosing their passwords and responding to offers supposedly from friends on 'Facebook'.
Graham Cluley, a senior technology consultant at Sophos, a computer security organisation, said: "When a Facebook login is compromised, it means that someone else, the hacker, has taken control of that account.
"When a hacker takes over a user's Facebook account, they can post images, send messages and access all of that person’s private information in one fail swoop. Facebook has had a lot of security issues which it is now trying to address."
He also warned that growing numbers of teenagers are hacking into the Facebook accounts of their school rivals in order to post malicious messages and photos on their behalf.
Facebook has declined to comment.