This 'tint your lights' movement is an off-shoot of the 'tint light covers' movement of the 1990's. That one was found to be started by Natural Selection trying to restore balance to the gene pool. I'm guessing this is the same thing.
For me, before there was the Thin Blue Line, there was the Blood Stripe! Semper Fi!
Our fear reminds us that we are not God, our faith reminds us that He is!
**DISCLAIMER** I'm not a current LEO, but have six years experience with two city PD's in NC and TX as a sworn officer. I'm in the process of returning to LEO work ASAP.