In the UK there's the common law notion of a "reasonable expectation of privacy". If you're in public then you don't, generally, have a reasonable expectation

In the UK there's the common law notion of a "reasonable expectation of privacy". If you're in public then you don't, generally, have a reasonable expectation of privacy, but if you're at home or at work then it's a different story. As far as I'm aware, though, this hasn't been tested in court since the GDPR has come in to effect, but I would be surprised if the (UK) GDPR is not interpreted with that principal if and when it does.