wouldn't that mean every piece of cctv footage that has me in it also belongs to me? i don't see it (no pun intended).
That is true in the EU in a number of circumstances. You can do a data access request for CCTV footage of yourself; I’ve successfully done this before, and some organizations give out CCTV footage this way often enough they have websites about their procedures. For organizations I know of, they blur other people in the footage.
Yes, of course. In European cities there are GDPR disclosures hanged on the lampposts on which CCTV cameras are mounted. The disclosure contains retention period and contact to data processing inspector where you can request the data. You probably need to specify the timestamps and haw to recognise you.
In commercial buildings the disclosure may hang on the wall besides main entrance.
Everything as designed.
I don’t think anyone has tested that in court. I wouldn’t be surprised if it should belong to you but fact that most CCTV footage is (or at least was) stored by small independent entities means that you aren’t aware that your CCTV data exists, or wouldn’t find it worthwhile to request it all.
It would be an interesting angle of attack against classic surveillance, though. If there are any vendors that store the video in some centralized system, so you can request it all at once.
But, I think there will be some hurdles, this case specifically relies on the fact that LinkedIn clearly doesn’t believe there’s any reason to keep this data private (they sell users access to it, after all).