Its a fundamental law: Observations affect observed systems.
The photons leaving a radar gun have momentum.
Therefore, when the photons strike your automobile, they push the car back-thus changing its rate of speed.
Thus what the radar gun records is actually the RESULT of its interaction with the oncoming vehicle, NOT the pristine data about its speed that the Smokies would have you believe.

The questions you need to ask yourself before you use this are:
1) Is the Judge smart enough to realize that the mass of the protons is so small that their effect on the measured rate is less than negligible... and
2)This interaction actually slows the car down, and thus you were actually going much faster. (oops fine increased)

1337 or 1am3?
I know, not exactly original, BUT... its my favorite defcon thang!