I always found it amusing when I'd walk into my local technical bookshop and see a whole shelf on crypto cracking with huge yellow stickers on the front reading, 'Banned by US censors'. Now I know they were serious.
I picked up technical schematics for the AT&T attempt to build a machine which would crack the DES algorithm (also banned by US censors) and the most amusing thing was that after spending a quarter mil, the thing still didn't work. Got the feeling congress isn't so much politically motivated to stamping out cryptography as it is towards preserving the bottom line; And given that i've spent good last 5 years at university studying cryptographic techniques, i'd like to think I could come out with a job at the end.
I'll be your mirror man. :)
Re: There are tools...
Yes, the tools are there. But more often than not you need to write them yourself. Only in the last few months have I got my scripts down so that not even a tmp file escapes my wrath (Yay for PERL).
The overheads for this probably aren't worth it, and there's still a few bugs. The package (as yet unreleased) needs to work at a relatively low-level to query the fs to see which files have been opened (it presently only works on x86 machines) and another cron to take an image of the complete filesystem once a day, compare it agains the previous day, see which files have been opened in comparison, and stores this and other data in a mySQL table. Then... every month, like clockwork, I switch my pootie on and it takes about an hour to archive all of the unused files for the period.
After that, it's just a matter of scanning through the .zip's and removing what I don't really need.
Seems a bit gratuitous, really. But it works.