When is it illegal?

File sharing is illegal if you're sharing content that is protected by copyrights to other users. Examples of where file sharing beomes illegal :

-Downloading or sharing a copyrighted movie.
-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.
-Sharing or downloading computer software (programs, games, etc.).
-Downloading or sharing a copyrighted TV show or program.