They want may credit for the composition of the icon. Despite it not seeming like a lot of work, it can be. Editing colour and cropping is work, as well as choosing good text.

As for fanart icons, icon makers should seek permission before using fanart as an icon base, most artists are cool as long as they are mentioned. :)

Personally, I’d like credit but I don’t demand it, as long as when asked they say they got it from me. Does that make any sense?

What's your oppinion on mini-movie/animated gif icons?