My (very) limited experience with them has indicated that they're just a big badger. Tough on traps when caught and very rare to see at random (which I guess isn't too much like a badger). If they're not in a foothold trap or body caught by a snare, they're of no danger to people at all.
Their tracks look like little bear tracks to me, but in deeper snow their tail often leaves drag marks.
I am sure (hope) someone with more experience can give more and better info as I'd like to know more too.
