Black flag with blue horizontal stripe. What is it?
 

I've been noticing the following symbol on some cars and trucks starting last year where I live, in Massachusetts. It is usually in place of the front license plate, or decal in the rear window of the truck.
http://www.1uptravel.com/flag/images/u/ufe-nbn.gif

Does anyone know what this symbol stands for?

did a google search and came up with this:

http://www.1uptravel.com/flag/flags/ufe.html

a symbol of mourning for police officers who have died. symbolizes the 'thin blue line.'

thanks for the interesting observation.

holy cow. Thanks rsl12. I've been wondering about it for months!

funny though--your pic comes from the same site where i found the info!!

It's not as strange as it seems. The website I was using to put up the original picture blocked direct access to the url soon after you posted your answer so I edited the link to point to your source.

Found a site where they were selling these things.
http://www.epolicesupply.com/thin_blue_line
Also an ebay auction
http://cgi.ebay.com/ws/eBayISAPI.dll...910216518&rd=1

I have seen those with "A" in the center of them. any clue what that specifically is?