From Slaw comes a mention of a fun database of law-related movie and pop culture references. There are no movies listed about Internet law. You could say that they don’t exist, unless you count Hackers. Which, quite frankly, you shouldn’t.
On the other hand, the general sci-fi genre has a great record on law and technology more generally. Last year’s GikII had two great presentations on this topic: Andrew Adams, From 1984 to V for Vendetta via Minority Report and Andrés Guadamuz,