no theft isnt infringement, the infringement happens when you distribute your product. the viewing experience is what is paid for by ticket, camming subverts the sale of the experience. if someone went into a strip club with a camera and recorded the live show thats theft as well. When the dancer produces thier own disk and distributes it thats in the same boat as a DVD release and any number of eyes can experience that video when the producer gets [guess ~ 50$- 100$] for a disk sale.

Theft almost doesn't seem like the right word for it. I'd compare it more like when someone sneaks into a movie theater without paying. You could argue about whether or not the people stealing these films ever intended to pay money to see them in the first place. Studios should figure out how much money they actually lost on ticket sales to pirates who would have paid for a ticket if they had no access to a cam version and then compare that to how much they spend in lawyer fees and IP firms trying to combat it. Considering how easy it is to find a copy, watch it, and suffer no repercussions, I'd say they either are wasting their money or not spending enough.