What are you allowed to film?
In short: You may film everything that belongs to your property and everything that is owned by someone else or on public property may not be shown on your video. For example, if you park your car on a public street, you are not allowed to monitor it. The right to film is strictly limited to private property. It is also better to point out to guests and visitors that the property they are entering is monitored (source: Verbraucherzentrale).