"Just about anything that is on this site, on the web, on TV, on CD's, on DVD's, in books & in magazines is probably copyrighted by someone."
Quoted from deviantArt's Copyright Policy.
So what does it all mean? Well it means you should not take photos of art, magazine covers, DVD covers etc. and post those photos here. Just because you took the photo doesn't mean you own the copyright to the content, if the copyrighted content is the main focus of your photo. Confusing? Should not be.
Be original, don't borrow too much and definitely don't steal. Or Santa will not be nice to you next Christmas.