… where it is illegal for you to know this number: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0  (For the non-technical, that’s a hexidecimal number.  We programmers prefer that notation.  In decimal, it’s 13,256,278,887,989,457,651,018,865,901,401,704,640.)

Why is this number special?  It’s the encryption key that controls the DRM (Digital Restriction Management) for every high definition (HD-DVD and BluRay) DVD sold to date.  If you are a very talented programmer, you can use that magic number to decrypt and back up your original DVDs.  A consortium of media companies claims they own it, and under the US Digital Millenium Copyright Act, they can censor anyone who publishes it.