Fresh off bringing an antitrust lawsuit against Apple and three publishers over e-book pricing, the U.S. Justice Department has set its sites on the over-the-top video business. According to the Wall Street Journal, antitrust investigators at the department are digging into whether cable operators are acting improperly to try to strangle competition from over-the-top video services in the crib. The investigation appears to have been triggered in part by Comcast’s selective application of data caps that favor its own streaming video traffic over that of competitors like Netflix and Hulu. Potentially more far-reaching, however, is the department’s apparent interest in the practice of authentication, by which users most prove they subscribe to a pay-TV service before they can access certain content online. That goes to the networks’ efforts to protect their lucrative dual-revenue stream business model. If DOJ puts the kibosh on authentication, the industry could be far-more vulnerable to disruption than it has been up to now.