The XBox One makes it easy for players to create and upload gameplay videos using a feature called 'Upload Studio'. Uploaded videos are viewable by any XBox One user. This seems like a useful way for gamers to promote the games they play, but there's a catch. In making the process of publishing gameplay videos so simple, Microsoft also made it easy to inflict foul language on random, unsuspecting users. Apparently this prospect frightened Microsoft enough that they added a profanity detector, which will temporarily ban offending XBox Live accounts from uploading more videos. This restriction apparently doesn't appear in the console's Terms of Use, which has some XBox One owners understandably upset.

Update 2013Dec05: Techdirt has more about this.