Letters from officials at both Stanford and MIT said they did not approve of copyright infringement, and would take appropriate action if King could cite particular instances of infringement.

But King said it was not feasible for his clients to investigate each individual Napster user.

"I'm disappointed in the attitude [the universities] have taken, which is 'we don't know anything, we don't have any responsibility unless we know anything, tell us who's infringing and then we'll take decisive steps,' " King said.

"I don't think there are any doubts that people know what Napster's used for, and how much it's used on college campuses," he continued.

Princeton University and the University of California system, among other universities contacted by King, are expected to respond to the request today.

In the meantime, King said he would not yet respond with legal action against the universities that refuse to ban Napster.

"We're going to try to keep a dialogue with these universities, maybe point them to some authority that they've ignored or are not aware of, that tells them they have a higher responsibility than just putting their head in their sand," he said.