What does this bumper sticker / window decal mean?

I’ve seen it occasionally for at least the past 5 years or so, in a number of different states.

It looks like a purple Devo hat with two black eyes (or wheels, even?) underneath it peering to the left. The background is white and there’s a black circle enclosing the main image.

Here is a very poorly drawn representation of it, done to the best of my memory.

http://min.us/mbhsM8XOea

Reverse image searching with google and tineye didn’t bring any luck.

Anyone know what this thing is for?

It’s the logo for the "Watch Your Car Program"TM: The “WATCH YOUR CAR” program is a national vehicle theft prevention program funded by the Bureau of Justice Assistance of the United States Department of Justice. It is a voluntary vehicle registration program designed to deter auto theft and assist in the apprehension of auto thieves.
Excerpted from: http://www.annapolis.gov/government/departments/PoliceDepartment/CommunityConnection/WatchYourCarProgram.aspx

See also: http://www.coolidgeaz.com/vertical/Sites/{AE188E70-DD7F-47BE-99EF-B58B70641DF9}/uploads/{6A222973-E361-4242-981D-7DD4CA464415}.JPG