Company has seemingly good intentions: so-called revenge porn has become a major problem in online world. A situation where after an ugly breakup, the other half of the disbanded relationship distributes the couple's intimate videos and pictures is all too common nowadays. Facebook has taken steps to prevent this in the past, too: company has used facial recognition to block such behaviour and has also shut down accounts found guilty of distributing unauthorized pictures.
But to send all the intimate photos and videos to Facebook? Company claims that they'll delete the material after digital fingerprint has been created. But we only have Facebook's word for it. And obviously, if there are copies left somewhere in their servers, it opens up endless possibilities for hackers to get their hands to material that can be used for extortion.
Company states that hashing can be done without sending the actual material to their servers, but you'll still have to grant them access to process the files in order to create the digital fingerprints/hashes.