I know bounties on questions help in getting answers. But it is also possible that some people award bounties to get perfect answers but after getting the answer they do not accept it. Has this happened before? Can we do this? Legal or not?
Whether they accept or not, they won't get rep they offered in the bounty (unless a moderator ends the bounty and return the rep to the OP with is only when a moderator found the question should be closed).
And if the OP doesn't award bounty. Half of the bounty will be awarded to the most upvoted answer.