Well you kinda Are dude . Your not supposed to post what you dont own here period. This is a Community for artists and there works. Reposting is what sites like tumblr and whatnot are for but not here. Im trying to be nice. Im not reporting you . Im merely warning you.
Well your the 1st case ive seen that immanently obvious. However. Im supposing this site isnt heavily moderated. However As a maker of content It urks me somewhat to see unoriginal content here. But Your call. It just insults the point of this site is all.
Look around a little and you'll see it (plus I know this will be mind blowing but I'm not very creative lol) and I agree it's not very well moderated at times, some of the admins will deal with only what they feel like dealing with and sweep the rest under the carpet, plus one could argue the point of this site faded away awhile ago. Sure there's still art here but it's become quite a place for some more sexual/fetish art pieces.
Pound signs before a word or phrase are referred to as a "hashtag" and will actually be used to mark keywords for people to find posts by. Using the @ sign before a name/user/group targets them specifically and will receive a notification as such.