What is the meaning of these "Blue Line" bumper stickers?

[Rockholm]

I see them everywhere around Boston. There are basically a black rectangular bumper sticker with a blue line though it. Looks alot the the HRC "Equal Sign" bumper sticker.
Any ideas?

[Bronco69]

1. I saw one in Dallas.

I'm curious too.

[Goldeneye]

2. is this it?

[Rockholm]

7. Yep, that's it!

[Goldeneye]

8. Its from this website..doesn't really say what it means though

http://www.mitchellproffitt.com/

[CottonBear]

3. I think it's a law enforcement member/support sticker.

From the saying "thin blue line."

[tridim]

4. Looks like you're right

http://www.frontlinedesigns.net/

Why do I have a feeling it's more sinister than this site lets on?

[CottonBear]

6. The RW secretary at my office dates cops.

One of her former boyfriends had those blue line stickers all over his vehicles. These guys are typically very southern, RW, pro-guns, pro-god, anti-gay. It's a macho law enforcement signal to other law enforcement types.

Edit: My friend lives next door to the sherrif in our county. No such stickers on his family vehicles or on his truck. During the week he drives a sherrif's department car. He is a black Democrat in an urban county. The guys with the stickers that I mentioned above are from a rural, conservative, white-flight community.

I'm more worried about the sherrif's German shepherd dog. They let him out last night and he wouldn't let me out of the car! I called my friend on my cell, she called Hugo and gave him a toy chewie and he left me alone after that.

[R3dD0g]

5. According to an old article on Arkansas Times

(archive link not available) they are to notify police that the occupants have a concealed carry permit and might be armed.

The Little Rock police vehemently denied it for weeks, but finally admitted that it what they were for. I don't know where they come from, if they're given out in a 'Welcome to Insanityville' package when the person gets his license or what.