I think that booing, in general, is justified. Mind you not for every little thing, but it is justified. How else does a fan voice his/her displeasure with how a team is playing? They certainly can't call up random players on their cell phone and say, "hey, your not playing up to your potential, get with the program." There isn't, as far as I know, a comment suggestion box by the dugout that Ned takes notes from on a daily basis. I think that if a fan wants to start a chorus of boos for Gagne (just an example, you could insert a lot of different names here) after he walks his first two batters and proceeds to get shelled, by all means do it, because no one in the dugout is gonna tell him that he needs to step it up. I don't think that boo means "you suck or you're a bum", its more like a chant to say "hey, we know you are better than this, let's go!"