It costs about ten bucks to fully recharge a Tesla and about one hour of time. You might break even if you earn minimum wage? But then, how did you afford a Tesla to begin with?
Even if we assume you use your time productively while charging ... it all seems a bit silly for ten bucks?
Yeah, that is the question. Because if the math doesn't add up, nobody would do it, meaning Tesla doesn't need to worry about it.
A real answer that didn't miss the point would be along the lines of "Yes, here's a news article showing that Tesla has algorithms that check energy consumption against mileage, or against a set of expected patterns." Another real answer would be "No, they don't. Here's a comment thread where Telsa users have talked about their experience with charging stations where they didn't run into such limitations." A point-missing answer would be "hey, bitcoin mining isn't that profitable!"
It would succeed no better than showing up with a barrel at a burger shop and start filling it from the free ketchup dispenser.
Not to mention the mechanics of converting the ketchup in the barrel to usable energy would be inefficient and convoluted at best. Better to find some other way to power one's Bitcoin mining rig. :)
Though, you could likely dodge any criminal charges by way of insanity in that scenario!