I might want to do violence upon you for some reason. Maybe I hate you. Maybe you're doing something that I don't like. If I'm lucky I can round up half a dozen buddies to help. But I don't have infinite resources and infinite reach, so my capability is rather laughable unless you live next door.
Buuuut, if I craft it just right, I can cause the state with it's practically infinite resources, infinite men with guns who kick in doors, etc, etc to choose to kick in your door and do violence upon you. (And the request usually looks a lot like doing their job for them "hey look over here there's this specific person doing this specific thing that you're supposed to go after", but that's beside the point.)
Same as how if I craft a request to a 3rd party server just right a few Kb of on my end can become dozens of Mb on yours.
The German police can't reach these guys. Hence why they're doxing them. They're hoping to structure things such that those who can reach them respond to the request (i.e. rounding up these guys will be a line item in some larger geopolitical context).