Oh, I prefer haruhi OP “Hare Hare Yukai”
Wotagei or オタ芸 looks like fans dancing with a singer/performer in a concert in order to give a boost to the live.
However, I guess since Wotagei goes beyond the “limit,” Wotagei is treated as a “different kind” of performance. Shaking arms, turning around… violent movements while raising a weird cry bother people.
Wotagei is like a performance of this Otaku people dancing around, singing and the likes, performing what like an anime character acts in performance.
Check out the Zombies dancing “Motteke Sailor Fuku”
But I don’t know it is taken, but what the hell Zombies chills my spine! They rock! DX
Wotagei is popular now on other countries, not only on Akiba.
Sure, if I want to dance who’ll stop me?
It’s the love of anime that surely makes a proud Otaku.
Just moé 
Great !!