The Fathom Five? Is that a joke? Was the really the name of a superhero group? That sounds like something Dungeons and Dragons nerds would name their clan.
Haw, Fathom Five.
It's not that they aren't legal, it's just you get charged for the crime as if they were real. Like if you robbed a minit-mart, you'd get charged with Armed Robbery.
I own quite a few fake guns actually, all leagally shipped to my house by FedEx.