foiling cinema pirates?

I saw this article on the BBC about experimental measures being developed in the US to block the video cameras of cinema movie pirates with white light.
It's a tricky one, and no doubt it's not just cinemas that might be interested in such a set-up. I was wondering if an effective means of foiling video cameras in cinemas might be to vary the frame rate of the film itself - thus interfering with the coherence of the video camera's constant frame rate capture - but on second thoughts that might be extremely complicated and cause people in the audience to feel ill.