In the German state of Bavaria, dozens of people are in 'preventive detention' because they might otherwise engage in climate protests, specifically around the car industry exposition IAA in Munich.
Apparently possible for a month there...
https://www.zeit.de/gesellschaft/zeitgeschehen/2023-09/letzte-generation-bayern-praeventivhaft-gewahrsam
Bavaria is a traditionally very conservative state. The Conservative party is ruling with an iron grip for decades.