No, demonoid isn't a trap.. but then again, it's a semi-public tracker. Anyone who feels like going on there and snooping will yield results and their newer torrents are public. Seeds can easily log you and report you to the company, like an HBO series torrent to HBO. If you invest in say, PeerGuardian, you'll note that alot of the IPs warned about pop up in any public tracker.
l0cke