Symbols and such are not copyrighted, they are trademarked. Artistic works are copyrighted.
Bitcoin is a trademark held by MtGox, on the dubious theory that "better they than someone else". There was some talk about them transferring this to the Foundation, but nothing came of it AFAIK. (And for the record, this forum is also hosted by them).
There's not to date been any enforcement attempts against any user, so you can probably go right ahead. The commonly used image/symbol for a Bitcoin however depicts a Thai Baht I think, which'd be a trademark of the Thai govt/central bank (I assume, haven't checked).
Instead of creating a new thread, I digged this old thread to know who owns the trademark Bitcoin around the world. What happened to Mtgox rights on the trademark ? Were they given to the Foundation (likely) or are they in the hands of the people handling mtgox assets ?
I found this link on reddit :
http://www.reddit.com/r/Bitcoin/comments/1s2vth/copyright_troll_trying_to_trademark_the_words/
