Don't be an idiot. There are fans of 1D and JB that are normal. Every fandom has its extremes. Tell me, when JB and 1D fans scream for them, is it any different from when fans scream for Eminem, or Micheal Jackson, or Beyonce during performances? No, you just have to bully them cuz you don't like the artists.
Seeing as how the stereotype for anime fans is social awkwardness and being losers, I'm sure they can spit those same words back at you.
If you think anime fans can't get extreme as music fans, try to remember the kid who killed himself cuz Itachi died.