Internet television streaming outfit Aereo has had success fighting off a multitude of broadcasters in court over the past couple of years to keep their business alive but their biggest battle is now upon them. The NFL and MLB are urging the Supreme Court to hear a challenge against Aereo as it is their belief the service is designed with the sole purpose of skipping out on paying retransmission fees to copyright holders.

In an amicus brief, the two leagues say those lost fees may force copyright holders to move content from free networks to paid cable networks like ESPN and TNT. The reason, they say, is that Aereo-like services can’t hijack and exploit paid cable network programming without authorization like they can over free broadcast TV.

Let’s look at the impact that moving to paid cable would have on broadcasters and viewers at home. At present, CBS, NBC and Fox broadcast roughly 90 percent of the regular season NFL games, all of the playoff games and the Super Bowl. The MLB, meanwhile, licenses about 400 games to broadcasters each year in addition to the World Series. Moving all of those from the big, free networks would have a huge impact on their ratings and advertising revenue.

Anytime the NFL puts their weight behind something, things get done. If you recall, the NFL was pretty much single-handedly responsible for ending the Time Warner / CBS blackout earlier this year. In my opinion, it all really depends on how serious the NFL is about pushing the deal. If they seriously threaten to take their content to paid television, it could spell disaster for Aereo in the court room.