Ticketmaster's parent company Live Nation says it's "only a theory" that more competition would mean lower prices.

The U.S. Department of Justice sued concert promoter Live Nation ... of ticketing innovation and forced to use outdated technology while paying more for tickets than fans in other countries.

Opening their venues to multiple ticketers and promoters could raise ticket ... use those amphitheaters," she said. That's exactly the kind of "tying" arrangement that is barred under antitrust ...