According to a recent U.S. District Court ruling, you may use trademarks when buying search ads. Just don't use the names in actual ads that consumers will see.
The Court also ruled on something that's completely passÃ©: it's okay to insert trademarks in your meta tags which are also invisible to consumers.
The comments in TechDirt are interesting, about the value of trademarks. At what point is do brands become generic terms? Can they get diluted? Don't stores sell multiple brands together, so why's this different?
J.G. Wentworth vs. Settlement Funding was decided in the U.S. District Court of Eastern Pennsylvania. Plaintiff Wentworth says that Settlement used its trademarks "to confuse the consumers and to divert potential customers away."
However, there was no violation found of the Latham Act, which covers trademark protection. See additional interpretation by Eric Goldman. Everyone's applauding in our industry, but this is only another case (and chapter) written on the matter.