This means that anything you put in a post on Facebook or in their built in chat feature (which many consider private) is being scanned. The details of the scanning are not clear and it is unlikely that Facebook will reveal them (unless ordered to do so). Once a message is flagged an employee reviews it to make sure it is not a false positive and from there they contact the appropriate law enforcement agency. After the revelation complaints have piled up stating that this type of scanning is a clear violation of their reasonable expectation of privacy. In order for your private communications to be monitored (at least in the US) it typically requires a warrant from a judge authorizing the monitoring. However, Facebook appears to be doing this on their own and then notifying the authorities who setup an investigation.
We wonder where this type of voluntary snooping will stop, although right now it seems that Facebook is aiming toward keeping child predators off of the site, we have to wonder what else is or will be flagged in their system. It also raises serious concerns about the simple fact that their employees can read the private messages that are sent between users. According to at least one lawyer we talked to the fact that Facebook is doing this might be more harmful than helpful. Because of the gray area around the way the data was collected in the first place it could be considered inadmissible, this would render the charges brought about because of the inadmissibility of the original evidence void as well. After all if I the police perform an illegal search of your house and then arrest you for what they find there, they will never get those charges to stick (just as the US DoJ about the MegaUpload case).
Facebook has already been accused of violating US Wiretapping laws with the way they track users even when logged out of the site. We imagine that they will face some serious backlash over this one as well. Although we agree that they have to do something to keep the service clean scanning everyone’s conversations is not the right way to do this. Now that Facebook is a publicly traded company the word of this serious breach of user privacy is sure to hurt their stocks and company value. Someone needs to put the brakes on Facebook’s runaway violations of their users’ privacy and soon they simply cannot be allowed to continue to do this without any repercussions.