Police body cams are typically only used while on-duty and in public, where there is no expectation of privacy. They also don't automatically send video into the cloud to be analyzed by a human for AI training, as mentioned in this article. Video is usually only retrieved if needed on a case-by-case basis.
Doorbell cameras are also typically pointed toward public streets, where again, there is no expectation of privacy. Even then, many people have been removing Ring cameras after they were shown to automatically upload video without user's knowledge.
> They also don't automatically send video into the cloud to be analyzed by a human for AI training,
Yet.
In Spain the typical doorbell camera is illegal. In an apartment building it is illegal to have a camera on the door that points into "common" areas even though these are still private areas vis-a-vis the general public.