Weirdos at night

I just had a student here telling me about a "deranged looking" person that came to the library over the weekend. The person sat at the computer next to the student and proceeded to look up chemical weapons on the Internet. The person eventually left but freaked out a few students. Granted this is the student's side of the story, and it most likely was a biomed grad student that found its way out of the lab for a moment to pass some time, but I wonder if was just a standard oddball. So far there have been no other complaints reported about strange research projects on the public terminals.