being 18 myself, I can kinda see it from both perspectives... I wouldn't want my parents going through my email or other private messages. I don't even like them looking over my shoulder when I'm looking at various sites.
I think a program that can pull up anything and everything from a kid's computer isn't the best idea. but I also think parents should be allowed to monitor somewhat what the kid is doing. I don't think filters are going to catch everything, especially if the kid is smart enough to figure out a way around it. so personally I think it would be better to have a program that just pulls up websites that have been visited. but don't go through everything, just spot check it every once in awhile. and definitely tell them about the program.
my parents were very lenient on the computer, the one we were allowed to use was in the basement, and they didn't really care what we did with it. it wasn't a problem, but I think it should have been a bit more regulated. I wouldn't mind knowing my dad would occasionally browse some of the sites I visited and see what I was up to, I don't have any reason to be ashamed of what I looked at. personally that would be better than them reading behind my shoulder... even if I was writing in German I'd still minimize the window when my dad walked by and watched me for a second
generally I didn't even like anyone being in the same room as I was doing whatever.
anyway, just some input, hope it helped