I play stepmania but I don't think there are legal MACHINES out there are there? Or is it just a hacked ITG machine? I know of a few that have been hacked and have 4000 plus songs.
Not in the classic sense, no. Technically the arcade doesn't have performance rights to that song, but I don't think anyone cares. Stepmania cabinets are easy to build and take down and so any suing of the arcade would result in them taking out the machine - not worth the lawyer's time since they make no money.
ITG is the closest to a legal arcade Stepmania cabinet there is, although Konami won ITG in a recent court decision.
Unrelatedly, check the credits down at the bottom of ITG1 arcade under 'Special thanks'

I never get tired of mentioning that.