[roywiggins]

They haven't been convicted of anything, they're being detained anyway. This is not the same as pre-trial detention, if Google Translate is a remotely accurate rendering of the linked article:

"Legally, this police approach is called preventive detention because it is not detention for a crime that has been committed. The police laws of the different states allow this for different lengths of time. In Bavaria, up to one month in prison is permitted, which may be extended by a judge for a maximum of another month.

The so-called preventive or preventive detention is very controversial. The relevant laws were originally created to prevent terrorists from carrying out attacks. However, this form of detention is now also permitted in the case of the “imminent commission or continuation of an administrative offense of considerable importance for the general public,” as the Bavarian police law states. Lawsuits against this have so far been rejected in Bavaria. However, a final clarification about the legality of this approach is still pending."