I had found two who was using my art, but there gone now.

Not cool?
Stealing art goes way beyond "not cool."
For someone who also has a Typhlosion sona, I will gladly report him.

Looked at some of their policies

"We will remove images and other copyrighted material as swiftly as possible if requested by the copyright owner, or if it's from a source that has publicly indicated that they don't want it distributed. Except in extreme cases (things that clearly fall outside fair use, etc), we generally won't remove anything else at the request of uninvolved parties, friends of the artist, and so forth."

People on F-list borrow images all the time, true he didn't give credit but he didn't claim it as his either. Ask him to remove the pictures and avatar, send a report to the administration.

If you don't have an account or anything then people reporting on your behalf need to link to this journal, as it should fit "...or if it's from a source that has publicly indicated that they don't want it distributed."

places like that make me want to check if someone has used my characters

Yeah, you need to look around cause I remember before some people used your centaur a few times

As has been said before, you need only contact the administrators of the site, or just the account-owner themselves, and ask them to take it down.

It isn't really a big deal though, ultimately they're only using your art as a reference for their character. If they're not making money off the art, or claiming the art is their own, then does it really matter if someone on a separate site is using some of your pics for their character? These people can actually get your artwork more attention by guiding interested people to the artwork's source, your gallery.

Don't get me wrong, if you still don't feel comfortable about it, feel free to request the pics be taken down, that's perfectly fine, I'm just saying it really isn't all that serious.

I'll also admit to using some of your artwork as a reference to one of my characters one there, and if you wish for me to take those pics down, just ask.

It's one thing to use as a reference, and at least youre being honest.

but to just up and take it without credit, thats just rude.

I do think the person should ideally go out of their way to let people know the work isn't theirs, and to provide the name, and preferably a link to the owner(s) of the artwork, and their gallery.

An alternative to what they're doing is just to not use the on-site gallery system, and just use direct links to the pictures on here as their references.

LET ME AT HIM!
I'LL TEAR THAT THIEF APART!
D8<

This is partially why I'm glad I'm not very good at drawing. I don't have to worry about people doing this.

The only people that can have the person's account deleted or the art removed are the original commissioners or the artist him/herself.

Thanks for the heads up. I let Koku know.