There was this one guy back in the Skyrim days who managed to get a copy like a week early and do a lets play of it. I don't think he was even aware that he had broken street date.
These street dates get broken all the time though, and there's a whole mess of stuff that happen around them. I haven't heard of any merchants getting in trouble for it, but then Ive only kept track of Bethesda's releases. Im sure other companies would be more likely to clamp down on this sort of stuff.