I just posted about this as it related to the iPhone and Apple calling jailbreaking "unlawful."

There are some restrictions of course.

*allow the unlocking of mobile phones to change carriers.
*allow the cracking of video game digital rights management controls to probe security flaws.
*allow the breaking of DVD encryption by professors, students and documentary makers so the clips can be used for education and commentary.
*allow the blind to circumvent locks on e-books to enable read-aloud features.
*allow the bypassing of broken or irreplaceable dongles.