Enough!
TOS = Terms of Service, referring to the agreement the uploader of the file has with the hosting service. A TOS violation means the hosting service has decided that the member who uploaded the file has violated the agreement.
The host can decide on a violation on its own, but usually does so when a third party complains. The third party could be the copyright owner, of course (that's fair), but it could be anybody, including third parties who have no involvement with the content at all, for example, corporate, political or religious groups with an agenda who claim to be offended by the material. They don't have to provide any proof, either.
We are entering a dark and dangerous period of uncertainty about this issue. In view of the developments of the past several weeks, it now stands that anybody who wants to share something online is guilty until proven innocent.
The burden of proof should be on the complainers! The file sharing hosts should be required to reveal who filed the complaint!
Outraged about this? Send an email to Congress! And don't forget to vote in November!