I think the main concern of most tor-users is that their real IP address (and hence location) is leaked.

For that, just a run-of-the-mill firefox exploit is all that is needed, and suddenly exploit code can do a wifi scan and get a very precise location.

Honestly, if this is a serious concern and you're already willing to go to all the other trouble, you may as well do your most sensitive Internet browsing from your car, connecting only to public WiFi in parking lots, in cities you don't actually live in, and never stay connected for more than a few hours at at time. Or take a hint from history's most secure criminals and don't do any of this yourself at all. Use paid underlings who fear you more than they fear prison and are willing to do time rather than rat you out.