I'm somewhat skeptical that this could even work for a few reasons:
1) How can they alter the sound so that a camera with a cheap mic can pick up the sound accurately enough for this to work without making it sound worse for the audience?

2) Even if they do somehow make the seat location ID work how will they know who sat there? Unless they assign seats and get the name of each person in the theater this is pretty useless

3) How will they know which theater the movie was filmed at, or which screen in the theater, or which time on that screen? Will every single individual screening have a different audio watermark?

Actually they do use a click track in the studio, though it is a pretty complex setup. A few years ago before the release of Train of Thought Mike (The drummer) had a contest on his forum where he posted the MIDI click track config they were using along with the key signature for each section of the instrumental song, with the goal being similar to the DT song without hearing it. The closest entry was played at the intro of every concert on the Train of Thought tour.

How is playing an instrument or doing any other activities associated with a band for 40 hours a week not work? I'll grant that *some* artists today do very little work, but what about the bands that spend hours every week practicing their own instruments, writing new music, dealing with the business side of the band (contracts, recording issues, etc...), and touring? Just because musicians are largely spending their days doing something they enjoy doesn't mean it doesn't qualify as work. Developing high technical skills on an instruments, learning music theory, and learning to apply that theory to writing good songs can take years of practice, and can be just as difficult as something like software development if you choose to make it so.

Could you explain that using cars?