In an attempt to monitor the activity on its platform, Facebook has removed over 300,000members from 120 closed Cybercrime groups.

Close to about 120 closed cybercrime and scam groups were identified on Facebook by security journalist Brian Krebs in just two hours of research on the 12th of April. Although Facebook deleted them hours after they were reported, research would likely turn up more groups, a few even bother to hide their schemes and most promote them openly.

“We investigated these groups as soon as we were aware of the report, and once we confirmed that they violated our Community Standards, we disabled them and removed the group admins,” said Pete Voss, Facebook’s Communications Director. “We encourage our community to report anything they see that they don’t think should be on Facebook, so we can take swift action.”

The deleted groups had an average of 300,000 members communicating in English, but Krebs believes there might be tons of other groups in more languages. The illegal activity appears to be flourishing on the platform as the groups handled activity such as spamming, wire fraud, account takeovers, phony tax refunds, and DDoS-for-hire. 419 scams and botnet creation tools were also identified in the research process.

“Some had existed on Facebook for up to nine years; approximately ten percent of them had plied their trade on the social network for more than four years,” Krebs writes. “As technology improves, we will continue to look carefully at other ways to use automation,” Facebook concluded. “Of course, a lot of the work we do is very contextual, such as determining whether a particular comment is hateful or bullying. That’s why we have real people looking at those reports and making the decisions.”

A significant majority of the now deleted groups advertised the sale and use of stolen credit and debit card accounts, while many others promoted mass-hacking techniques to take over online banking services and accounts on Amazon, Netflix, PayPal, and Google.