Can it compress 3d videos? That seems to be a real challenge.

http://www.noulakaz.net/weblog/2007/03/18/a-regular-expression-to-check-for-prime-numbers/ describes a way to use regex to check if a string contains a prime number of ones.
Here is the actual regex. /^(11+?)\1+$/
Ironically, this isn't even a "regular" (in the CS sense) language at all, which just shows how powerful regex really is.