Yep you can unlock freeview boxes, not hard at all if you follow some basic instructions and use some software off the net.

But one of the forums i use was nearly shut down when someone started giving out that info, so its best left as a subject not mentioned on passionford in an detail or it will face the same legal action.

Please dont PM me for details, its not something i want to get involved with, but im just saying it can be done if you look into it, you just need to get some numbers out, put them through a simple equation and type in a key.
A web search and a bit of time should reveal the rest for those interested