Who ARE these people!?

Today, I had a long conversation with somebody over instant messenger. We'll call him Fred17, even though that's not his real screenname.

Fred17 messaged me and said he needed my help catching a guy who had been throwing chili on his car and testing his door to see if it was unlocked. Among other things, he needed help figuring out how to get a night-vision camera.

I conselled as best he could, including such sage advice as "Uh, you could get a camera and a motion-sensor spotlight from Radio Shack, maybe..." and "Um, getting a gun and trying to lure him into your house so you can shoot him and claim self-defense is probably a bad idea." I also learned that he knew who was doing it, and that he couldn't confront him directly due to a police order after he sent the guy a threatening letter.

Fred17 listened intently, and eventually thanked me for my advice before signing off.

This leaves me with just one problem.

I have no CLUE who Fred17 is.