Yeah it varies. In my country you only need to participate in the conversation to be allowed to record it.

If your country is part of the EU (aka having to comply with GDPR)? If so, you may be surprised to realise that things have really changed in the last few years. GDPR being only part of the reasons why. It’s not the same in every single country, but the shift is happening in favour of the plaintiffs, in the name of privacy, even when the scene was recored or snapped in a public space.

in France (my country) and in Germany it’s obvious that this trend is now in favour of the plaintiff when a few years ago its was still in favour of the photographer or videographer.

Nowadays, imho, no photographer/videographer in the EU should take the risk to publish any image of an identifiable person without having the written permission to do so from that very person (and that authorisation should also mention where it will be published and if the person should expect any compensation, and how much it is if there is any to be given). Street photography/videography in the EU is turning or already has depending the country, in a real booby trapped activity no matter if you’re doing it as hobbyist and not as a pro.

France, where I live, and Germany and two of those EU-ccountries where I would not take any picture and publish them without a written permission — and I’ve been doing street photography in France as a hobby for the last 30 years or so. The risk is too real to get into legal troubles. Even in the UK, a country which was alsways more welcoming too street photography (it was clear no one should expect any privacy while in a public space), things have started to shift. Add to that the complexity layer of the many ‘not public’ or ‘not entirely public spaces’ mixed within the public space, plus the terrorist or safety considerations, regulations or exception-rules and you get the real mess we’re in. It’s still much better in the UK, though, but well, like I said street photo is a hobby for me, not something I’m willing to take any risk or worry for (lawyers are expensive and my time is much more precious than money). So, I gave up on street photography almost completely. Instead, I started to… sketch street scenes.

Edit: clarifications.

Photographing or filming someone in a public space has always been very legally distinct from recording a private conversation in pretty much every jurisdiction.