It depends. I can hit you like any other user, 'cept I'm good (or bad) for 50 points at a shot.
I can also go into the admin screen and type in any number I feel like. (How about zero? You like zero? If zero's not good, we can try minus ten.)
If your signature says anything to the effect of "Karma is (always) returned," you're a candidate to join the Elite Society of People Without Karma, because "giving karma back" is cheating. If you're reading this and feel a need to go fix your signature, please do.
Silly person. I will tell you what happens next, though.
At 35,000 your legend changes from "(User) has spent way too much time here" to "(User) is a cheater, because no one can get that much K honestly." I can hardly wait to see whether the first guy to hit that gets stuck with it forever. Will his buddies send him red to rescue him? Stay tuned.