According to a report from InformationWeek, a San Diego-based law firm has filed an antitrust lawsuit against Apple for “illegally maintaining a monopoly in the digital music market by failing to support Microsoft’s (MSFT) Windows Media Audio format.,” notes Fortune. “According to the complaint, Apple controls 75 percent of the online video market, 83 percent of the online music market, more than 90 percent of the hard-drive based music player market, and 70 percent of the Flash-based music player market. Yet among the major digital music vendors, Apple is alone in not supporting Windows Media Audio. The suit estimates that Apple could license WMA from Microsoft for less than $1 million — or about 3 cents for each iPod sold in 2005.”