Yes, but...
"pornographic" or not, it's still 400 pictures of kids you don't know on your laptop.
Sure, the cops may be magnifying kids in the background, distorting the focus or whatever, but do you have 400 pictures of kids you don't know on your latop? If it were just these pics I'm not sure I'd feel this way, but in the context of a bunch of animal porn which was bought online... well, I just think a lot of people who are talking about 1984 etc are forgetting the simple fact that - "pornographic" or not, 400 pictures of kids is worth a question or two, certainly IMHO.
The notion that the british police are on a crusade to convince anyone of anything is a bit simplistic to me, and I honestly don't think that investigating large collections of kiddie pics is somehow a million miles from their job.
Fact is that even if my best mate was caught out like this, my first question - assuming they weren't planted - would not be "what did you do to anger the cops" it would be "what the fuck were you doing with 400 pics of kids on your hard drive.
Privacy is one thing, but people abuse privacy just like they abuse kids: to read some comments here it's like people are trying to deny that molesting kids is a problem, people defending right to privacy seem to rather not discuss that aspect and like to frame anyone who does as a hysterical paedophile. IMHO it is not unreasonable to assume that someone with 400 poics of kids he doesn't know might need some help.
Funnily enough, it's not the law that then proceeds to witch hunt and stigmatise these people: it's the public and the media. I get the impression that it's easier to blame the cops for this situation than the more complex blame that is carried by our messed up society.