(Just to be on the safe side, no mainpage!)
I'm a scientist and I work in infectious diseases. I sometimes wonder if one day I am going to get a knock on my door because of some of the things I search for online. I am in the middle of putting together a preliminary budget for a grant proposal, so I am trying to find sources for diptheria, pertussis, and tetanus toxins. Not the sort of thing your average person is looking for. I also spend part of my time in a bioterror response lab, so it's not unusual for me to be looking for resources on several different potential bioterror threats.
So what's the thing that's going to have someone knocking on your door wondering what the heck you're up to?