You were right to get pissy.
First Purple Tentacle posts "His" new poster. It wasn't until his double-posting did he mention that he didn't make it. But again, never did he link people to the larger version or give credit to the person who made it, which would be Javier Burgos.
The point of this thread is to create new, or large versions of LucasArts (or similar) posters. Posting a 200X300 pixel image really wouldn't look good made poster-size.