It is *probably* legal in the USA for Debian to distribute it. However,
no one wants to find out the hard way that I am wrong about that, and in
any case it's easy to get it elsewhere.
Actually, probably NOT legal to distribute in the U.S., according to the
DMCA. See
http://en.wikipedia.org/wiki/Digital_Millennium_Copyright_Act
Any software or hardware meant to bypass or disable copyright protection is
illegal in the U.S.
I have read the DMCA. I have also read many of the court rulings
pertaining to it and to DVDCSS. The DMCA anti-circumvention provisions
are not nearly as broad as they are generally believed to be.