The surprising thing and what allowed them to go after Megaupload is that they had leased sevrers in Virginia. Which is quite stupid if they were aware of it, it is not as if the US has no history of trying to suppress copyright infiringements. But if the other sites don't have anything to do with the US, the government can't do anything to get them. Even then, it is not as if the filesharing services are openly based on copyright infringement - of course their business model is based on it and it is no coincidence that they started appearing right after the crackdown on direct P2P file exchange, but this is not what they are advertised as, it is just a place to store your files (and BTW, there probably thousands of people who need to access important personal files that they stored on megaupload who can't do that now - it must really suck for them ). But there are also very useful search engines such as filestube that really can't defend them in any such way (obviously there isn't much to be searched for that isn't copyrighted); expect those to be targetted at some point too..