Someone's about to get f**ked

Yes

What an ingenious use of road signs, in the UK they just warn of congestion etc. Although I don't know what I'd need to do if I saw one that had a message like that on.

Call emergency services and tell them your location. Usually they’re posting because they have no idea where the vehicle is. They do this in the US for missing kids and adults. It’s good but has some problems. I got surrounded by cops once bc my car was similar to the one on the sign (same color, suv, and the license plate started with the same letters.) it was terrifying