Is file sharing illegal?

No, it's 100% legal. In no state in the United States or in any other country is file sharing illegal. However, if you're sharing content that is protected by copyrights so other users it is illegal. Below are some good examples of where file sharing becomes illegal in many places around the world.

1. Downloading or sharing a copyrighted movie.
2. Sharing copyrighted songs (music) to other people who have not purchased those songs or downloading songs from other people when you've not purchased that song.
3. Sharing or downloading computer software (programs, games, etc.).
4. Downloading or sharing a copyrighted TV show or program.