I work for a company that is distributed over several branches across different countries. Every once in a while we're having these group video calls/conferences where all branches participate and every time one of the branches makes a presentation to the others. Our branch is the smallest (less than 10 people).
Recently our branch was the one to make a presentation and one of my co-workers was in charge of it. The problem is that his slides had photos and videos of his co-workers (myself included), without having asked for anyone's consent. In fact, nobody was aware of the presentation and its content until the moment it got presented in front of the entire company.
There was nothing directly offensive in the content of the videos and photos that were shown but I personally felt embarrassed of some shots of myself that I didn't like and wouldn't have approved. I don't know whether there is a legal issue behind this practice, but at least ethically speaking, I believe it's wrong. The same colleague has done similar things in the past, such as making a poster with professional photos of co-workers he found on social media and then posting it on LinkedIn.
Any advice how I should deal with this? I want to say in public in some Slack channel that I'm not ok with this practice. But I'm not sure of how to approach this in case they claim that this behavior is legally and ethically acceptable and imply that I'm just being weird.
UPDATE: HR informed us that this practice is both illegal (GDPR) and against company policy. The co-worker in question has been informed.