In a previous discussion it was determined that most magic tricks aren't patented (for fear of revealing the method) or copyrighted (only the way it's written down in a book or recorded on a DVD or video is copyrighted). However, isn't exposure of commercially available effects considered [[piracy]] then?
I don't see how. It's possible that stealing someone else's trick for your magic show might be piracy, but describing a trick in an encyclopedia article shouldn't be. We're not reproducing the trick, just describing it.