It's not so easy to "legally" declare someone a stalker and get a restraining order. After all, Germany is a free country, and it's a very important and fundamental civil right to go wherever you want whenever you want. The police can't just go up to someone and tell him to go away - they simply don't have the right to do that. Also, the police are not allowed to take pictures of alleged stalkers - because that would be a violation of privacy.
If you want to get a restraining order against someone, you have to convince a judge that you're being stalked. And for that, you have to present reliable evidence, like fotos and videos.
