The major studios Fox, Warner Bros., Disney, 20th Century Fox, Paramount and Universal sued the Sunnyvale, California, upstart last month. They are seeking monetary damages, and want a judge to shutter the fledgling site for allegedly running a business based on copyright infringement.

But Zediva’s countersuit claims it is nothing more than a digital version of a DVD rental store.

Zediva allows customers to pay $1.99 to rent and watch a DVD online — movies not yet available on Amazon, Netflix and iTunes. It purchases DVDs in bulk and plays them for customers on request, according to its court filing. However, the studios claim that, unlike traditional DVD-rental stores, Zediva needs a license because it is transmitting “performances of movies to the public over the internet.” (.pdf)

Here’s a nugget from Zediva’s counterclaim, filed Monday.

“The only difference between watching a rented DVD on the DVD player in one’s living room and watching a rented DVD using Zediva is that rather than connecting to the DVD player with a short cable, Zediva lets users connect to the DVD player over the internet.” (.pdf)

Check out our analysis of the legalities of the service.