Just a note on music - a recorded version of a song can be copyrighted, the notes that make up the song are not copyrighted, but rather published. An artist like Wierd Al does not need permission to remake a song from another artist (though it's still polite to ask) either in it's original form or a varied form. However, once he does, he will need to pay royalties to whoever owns the publishing rights. If he wants to include an actual soundbite or clip from the artists original CD, then he would need persmission to include the copyrighted work (though many musical artists seem to feel it's better to not ask, and then sort it out in court later). As for the oft mentioned situation of Walmart - they would be completely within their rights to ban people from their store. In what seems like an earlier life now :) managing a large retail store whilst in college, people that attempted to shoplift were regualrly banned from the store for a period of at least one year. If they returned they could be subject to prosecution for trespassing (the same situation was carried out in a couple of situations as well). Bottom line, a store is private property. It can choose to sell to who it wants - try standing outside Costco and claim they are voilating your rights since you are not a member and they won't sell to you and see how far you get.