A friend who sells books on eBay often sells used copies of the Jane's books (Jane's All the World's Aircraft, Jane's Fighting Ships, etc.), the annual editions of which sell new for $900+. He's listed many of these over the years, but recently out of nowhere he gets an inquisitory e-mail from Jane's, demanding that he inform them of the source from which he obtained the books, and strongly suggesting that he not list them anymore because the reduced prices he gets for resale are "diminishing the perceived value of our products." He was tempted to tell them what to stick where, but as he put it, "the next step may be legal, and right or wrong, I don't want to get into a transatlantic pissing match over this."
(So now, he sends any Jane's books he finds to me, I list them, and we split the profits. And no nastygrams from across the pond yet. Yay for me.)
A good example, though, of how even a legally misguided implied threat can intimidate someone. If my friend sold nothing but Jane's books, he'd be more inclined to fight, but he does a decent business without them, and just figures he'll avoid getting into something that he has neither the time or money to deal with.
Yeah, unfortunately eBay will pretty much always follow through on a requested auction takedown from a content producer. They just don't want to be involved in their lawsuit.
eBay's business is in the second-hand sale. They have a strong interest in this practice to be legal.
In English, every word can be verbed. Would that it were so in our programming languages.