Context: the Thin Blue Line is symbolism for the role of police in maintaining public order. It has been co-opted by the alt-right. There is also a Thin Red Line to represent nurses. The French Wikipedia happened to use it in a legend to explain what the red lines on a map mean.
Fucksake. I’m pointing out that every one of your comments, at the time of their posting, we’re already answered by comments above them. Using emojis seemed a gentler way to convey this, but clearly a more blunt instrument is needed with you, friend. 🤫