UK useage.

The police in an area notorius for it's highcrime rate eg Whitechapel in East London, The Barton Hill area of Bristol, Bootle in Liverpool, the cornish town of Bude etc.

So called because said police see themselves as the only thing preventing an out break of anarchy
With 19 muggings, 34 assaults, 4 street fights, 7 car jackings, a rape, a murder and only 6 police the thin blue line is being streached tonight.
by black flag June 2, 2004
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the banding of all cops in any state despite right or wrong. The reason why NYC police only have cameras in their highway cars
All police rely on the thin blue line
by Anonymous November 2, 2003
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Thin Blue Line is the symbol pedophiles use to identify each other. Usually worn by racist police and their supporters.
The Thin Blue Line symbol, I would argue, is positive from the Canadian policing perspective and certainly a Calgary policing perspective - Calgary Police Chief Mark Neufeld - 2021
by lolwtfbbq42069 March 24, 2021
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