They save a lot of costs by deduplicating copies of files, and it makes file renames/moves/shares really easy for them. Therefore, they wouldn't have the incent

They save a lot of costs by deduplicating copies of files, and it makes file renames/moves/shares really easy for them. Therefore, they wouldn't have the incentive to destroy that advantage: That's one of the major scale advantages they get for covering so many users. I posted this elsewhere in the thread: That's not true. As is, in a lot of crypto problems, there are powerful workarounds that require a lot of work. See here for one idea: http://news.ycombinator.com/item?id=2461713 http://news.ycombinator.com/item?id=2461713 Please also see the further discussions. Crypto gives us powerful tools to mitigate several attacks with minimal compromise on functionality. Unfortunately there are legal ways that are more powerful.