So, Ignoring those who decide that carrying a LOADED GUN will solve problems
.. Back to how to deal with tailgaters...
Personally, If someone tailgates me (Bear in mine i only own a motorcycle) i do one of 3 things:
Option 1:
Slow down / move over to let them pass
Option 2:
Say "F*** Y**", twist the throttle and filter a little until im a good 1/4-1/2 mile ahead of them.
Option 3:
Have fun with them by slowing down, see how slow they deal with until they flash/beep me.. Then follow option 1.