Giving the answer to an obvious homework problem/test question does a disservice to the students that actually try; the ones who respect themselves and take their education seriously. In fact those students may get a lower grade than the loser begging for answers because they don't get the benefit of an experts knowledge. Also, because the serious student may struggle for a longer period of time figuring out problems, they have less time for other classes so they have to work harder.
IMO the losers should be allowed to fail. I sure would give a -1 for giving the idiot the answer and another for hurting the student that tries.