You wouldn't know it to look at them, but those red vending machines full of DVDs -- you know, the ones sitting outside McDonalds -- may be the biggest threat to the big box video stores since Netflix.

Redbox has announced that they'll be renting their half billionth DVD this week, just five years after they debuted with 12 kiosks in Denver, Colorado. Now boasting over 15,000 locations in 48 states, the convenience and low prices -- Redbox charges a flat $1 per day fee per disc -- have made them a major player in the video rental industry.

And the studios that produce the DVDs are split on whether or not that's a good thing.

Back in October 2008, Redbox, which is jointly owned by Coinstar and a subsidiary of McDonalds, filed a lawsuit against Universal Studios, alleging that the entertainment giant was abusing copyright and engaging in anti-competitive behavior. Universal had tried to force Redbox, who buy their discs from wholesalers, to sign the same sort of revenue-sharing deal that the big studios have with Blockbuster and Netflix. The deal would have limited Redbox's ability to resell used discs, decreased the number of DVDs available for rent, and taken a cut of their profits, to boot. Redbox understandably said no.

When Redbox declined to sign, Universal threatened to cut off the wholesalers who sell to Redbox, and to place a 45-day wait on the availability of new titles. This is, simply put, illegal. It's a violation of antitrust laws. So Redbox sued.