Those who take all the time to bootleg it are already investing more than would be required to make the money to watch the movie. If they're that avid about their movie-watching, nothing's going to keep them from going to the theater's to see it... even if they did get a sneak preview. If the first matrix was shown in the theaters again, I'd go see it. And I've watched it several times (non-bootleg, although I admit the first time I watched it was on a friend's bootleg copy... and I still bought the movie, just because it was so good.)
That doesn't in any way justify bootlegging. But I really do think that the majority of bootlegging is done "because I can" and is largely harmless. It's also non-enforceable. That's why we have the 21st amendment. It wasn't because we as a nation decided that alcohol was bad and then recanted our position a few years later. It was because the 19th amendment became such a joke that we just had to introduce the 21st to avoid hypocrisy.
Now I'm sitting back, twiddling my fingers, and thinking about the RIAA and ways in which history might repeat itself...