"517 copyrighted movies and software programs. Grokster’s name is apparently derived from Napster, it too initially offered an OpenNap program, its software’s function is likewise comparable to Napster’s, and it attempted to divert queries for Napster onto its own Web site. Grokster and StreamCast’s efforts to supply services to former Napster users, deprived of a mechanism to copy and distribute what were overwhelmingly infringing files, indicate a principal, if not exclusive, intent on the part of each to bring about infringement. Second, this evidence of unlawful objective is given added significance by MGM’s showing that neither company attempted to develop filtering tools or other mechanisms to diminish the infringing activity using their software. While the Ninth Circuit treated the defendants’ failure to develop such tools as irrelevant because they lacked an independent duty to monitor their users’ activity, we think this evidence under scores Grokster’s and StreamCast’s intentional facilitation of their users’ infringement. 5 Third, there is a further complement to the direct evidence of unlawful objective. It is useful to recall that StreamCast and Grokster make money by selling advertising space, by directing ads to the screens of computers employing their software. As the record shows, the more the software is used, the more ads are sent out and the greater the advertising revenue becomes. Since the extent of the software’s use determin es the gain to the distributors, the commercial sense of their enterprise turns on high-volume use, which the record shows is infringing. This evidence alone would not justify an inference of unlawful intent, but 5 Of course, in the absence of other evidence of intent, a court would be unable to find contributory infringement liability merely based on a failure to take affirmative steps to prevent infringement, if the device otherwise was capable of substantial noninfringing uses. Such a holding would tread too close to the Sony safe harbor."