--snip--

But now my bigger concerns are how can I know if my computer, my
files, and all my personal information will ever be safe anymore? And
what if they were looking at something illegal for instance that left
some kind of traces behind that I can't see and that could somehow be
retrieved that could potentially get ME into trouble? This is really
upsetting. I'm really thinking about going back to carbon paper. You
can't hack that.
--snip--

Most important rule :

When somebody has physical access to your computer then there is no real
security if he really wants to circumvent it (and knows enough).
Its like having doors locked in your house, using correct tools thieves
can still get in from the door or thruogh windows ( walls whatever).
Locks etc just slow down the process.

ismo