It's amusing to always have this US-centric view touted as some ultimate truth while lacking any nuance. I live in Germany and here there is absolutely an expectation of privacy in public spaces. The individual rights (privacy) are balanced with the collective rights (freedom of press) and both are allowed to exist, because based on the context of the situation one right can prevail on the other. To give you some simple examples: if I go to a public event, a political manifestation, then no: no expectation of privacy. But if I am walking around with my family in a park, yes there's absolute expectation of privacy even if I'm in a public space. Context matters and it's impossible to have just one broad and vague rule covering anything. Also keep in mind that a public figure automatically has lower expectations of privacy than a private citizen. While I can sue a paper for publishing a picture of me slacking at work, a public figure most likely cannot or would lose in court because the right of the people to get informed of his behavior is higher than his right for privacy. Who gets to decide? A healthy judiciary system, not "those in power".

Another interesting nuance of the law in Germany is: it's almost always illegal to take pictures or video of people that show their suffering or struggle. You cannot take a video of a man having a mental breakdown for example. Is this universal? No, of course a journalist will take a picture of a suffering man in the cold to send a message about inequality. If he ever will be sued it will be the judge to decide if in this specific instance the right of the individual or the right of the collective right should prevail.