It's a mess in Europe. It's different everywhere.

In the Netherlands you can record, but only share it with the cops and otherwise you need some clear exception (e.g. dashcam images with minor accidents to your insurer). In all other cases you can either not store them, at least not publicly and all cloud falls under public, or have to inform everyone about their presence on the images, or blurr every identifiable mark (e.g. faces, number plates, names etc). Pretty sure all cloud door cams violate that. So the cops sometimes ask for people's doorcam images, and they are allowed to do that, but likely the people providing them will have recorded it illegally due to it being stored on some cloud account.

This question has already been answered by security footage videos and as long as they are overwritten withing a certain time, stored non publicly and only shared with allowed officials, it's ok.

There are exceptions, but very limited, like clear public good (e.g. whistleblowers).