Really? What is the proper response to a tailgater? I can think of three possibilities---

1) Continue the current action, allowing someone else to take my safety into his hands.

2) Speed up and possibly drive faster than is safe for road conditions.

3) Slow down and force the tailgating jerk to pass.

I usually slow down but there's nothing funnier than a brake check. Watching some tailgating nutcase crap his pants gives me a chuckle.

Of course, the fact that I was rearended at 50mph by a kid in a sports car who wasn't paying attention may color my actions....