Just my own personal observation, but Disney copyrights are violated all of the time, and sometimes it seems that how serious Disney takes the violation depends on a: If Disney ever learns of the violation, b: the nature of the violation and c: what lawyer is assigned the task of handling the complaint. Every so often you hear about the hammer coming down on something innocuous, like a mural in a public common area that features Disney's likeness of Winnie the Pooh, or a t-shirt showing Mickey flipping off bin Laden. Disney will often take a violation more seriously if the characters are doing decidedly un-Disney things. They look the other way when it comes to non-profit endeavors (church groups with their own t-shirts). They REALLY have a bug up their butt about people who create costumes that look like Disney characters, not only becuase of the copyright violation, but because the person in the costume might not be playing the character the Disney way. That, more than anything else, seems to be the sort of offense that will generate the most notice.
Even still, once in a while, you'll hear a horror story about a threatening letter going to a hospital with a Disney mural in the children's wing, or something like that. Like I said, depends on the lawyer working that case. But more often than not, complying with their request/demand to remove the copyrighted image settles the matter, unless, as I said before, you've either made a lot of money violating the trademark, or they feel you've somehow cheapened the image in an un-Disney way (or a combination).
