Title basically says it all. Remember that you technically have to have permission to repost something on the Internet (such as GIFS or photos). Some photos can be used freely, but some photos (if they weren't free to use), the owner could see it and actually sue you for theft!
I know the chances are unlikely, but really, be careful with what you post! A teacher at my school was sued for reposting a photo that wasn't free to use.
I don't mean to scare anybody, but I also don't want anybody to get into trouble because of the forum (Especially because you can't blame it on THT because you agreed to that in the TOS).
So ya, be carefully with what you images you post! Hopefully this was a good reminder. I just stick to not posting any photos.