Lol yeah full stadions doing that stuff? You got it from the American TV?
Just a couple of ppl doing this(100 or so) But yeah still it's fucked up. But it's not because they are "just" black(well for Lazio it has todo with it

) But they wanna "hurt" the feelings of players, so he will start playing worse, and their team will win. For example, one soccerplayer had a car accident and killed a person with it. And they were making car noises. When jewish teams play, they make gas noises etc.
And yeah I agree it sucks. But those so called "die" hard fans(which they are not) have a lower IQ, then the goals that are made during a soccer match.
Andre