A recent post on TechCrunch.com showed massively retweeted screenshots from a user who’d found that their DropBox account had frozen a file transfer due to a DMCA violation notice.After some heavy speculation on the sketchiness and surveillance tactics of the cloud sharing company, it turned out that yes, DropBox does monitor transfers for information that contains hash functions from a prearranged list of DMCA blocked files but that the system they use doesn’t actually view the contents of your transfers. In fact, it’s been in use for a long time now. Instead, what DropBox does is passively monitor the hash functions of transferred files to make sure they don’t match hashes from a large blacklist of files that had been previously targeted by previous DMCA complaints. Since each and every file spread on DropBox has its own unique hash key, they can immediately tell if you’re trying to move around DMCA blacklisted files. Check out the original tech crunch article for more of the dirty details on how this works. How Dropbox Knows When You’re Sharing Copyrighted Stuff (Without Actually Looking At Your Stuff) – TechCrunch Featured photo credit: Copyright-_all_rights_reserved/Wikimedia.org via upload.wikimedia.org