They're regulated. Not German nor a lawyer but my understanding is that security cameras should only film private property (or as much as possible) and constant

They're regulated. Not German nor a lawyer but my understanding is that security cameras should only film private property (or as much as possible) and constantly running dashcams aren't allowed. It seems you're only allowed to record when something is happening but a dashcam which deletes the records unless you save them seem to be fair game