I think the MAJOR issue at hand is the clearly non-defined policy in the steam workshop rules about content submission that doesn't belong to you, nor created by you. I think somewhere along the way that concept was overlooked--or at least I didn't see it when yesterday I skimmed over all the information I could find about the steam workshop.
Especially for something where the possibility of money exchanging hands may occur, it seems obvious there should be a theft-policy defined somewhere. Did I miss it somewhere?
My point was it's only a problem with models that have been released. If you put them out there for people to grab then you have to worry about it, which sucks because you can't share first...
But there have been TONS of 'rip-off' submissions already with no financial worries because someone is just posting the pictures they found on a website. Not the actual models/textures. So Valve knows and can just delete them.
Main issue being annoyance and screwing with possible votes.
There was one guy posting a tons of polycount item pics and claiming them as his own. He was reported for sure.
If your models have also been posted I guess you just have to keep a good eye on submissions and report to Valve. I'm sure they'd also fix the issue if your stuff appeared in game to someone else's credit if you had proof. Obviously a post here with a date would be good proof.
But maybe that person would still get an initial sum of money, or maybe a few sales...
I still feel that the submission site was half thought out and still a bit fuzzy and dificult to deal with. (Not being able to use anything other than the bip_head bone...)