I don't see the big problem here.
A very small number of people have chosen to take characters from what could be classed as a "Furry" cartoon as their avatars.
It's not a fad. If you wanted to see a real Avatar fad, you should have seen the CookieMonster Fiasco, and I mean the first time around.
Calling this a fad is like calling out anyone who has an avatar with a character from an Anime as being part of a fad.
Also, to the people going on about how disgusting it is to be spreading "furry" around the forum's, so what?
They're not spreading anything researchographic around nor are they promoting being a FurSuit wearing furry.
This is actually a pretty low-class form of "Furry Art". It's more cartoonish than anything else. Sure, the characters are anthropomorphic but it's not disgustingly so.
The only problem we should have is if large amounts of "Furry Art" are spread around including those of a less "childish" nature. Until then, keep your socks on, it's not as bad is it could be.
I can't say I agree with Furries, but there's no problem with a few members going around with avatars of cartoon characters. /myopinion