The Grand Theft Auto V PC subreddit has posts from users who have found themselves banned from playing Grand Theft Auto V due to the use of mods. There is some confusion about what constitutes a bannable offense, as they say that cosmetic mods are allowed. Rockstar is not being more specific about what is not allowed, but there are a bunch of reports from users banned for using mods that expand the player's field of view, so users should be very cautious about what modifications they choose to install. Thanks VG247.