The Independent is not a trustworthy journalistic outlet so I'd recommend reading this link (https://www.theguardian.com/uk-news/2022/sep/11/republican-proteste

The Independent is not a trustworthy journalistic outlet so I'd recommend reading this link (https://www.theguardian.com/uk-news/2022/sep/11/republican-protesters-arrested-king-charles-proclamation-events https://www.theguardian.com/uk-news/2022/sep/11/republican-p...) first. This type of stuff is very concerning but it's been around for a while. Section 5 of the Public Order Act is essentially a catch all to arrest (and typically take them to a police station and de-arrest them). It's fairly common during disorder and I've seen it personally. @TotoHorner above/below makes the joke "cool to protest provided it's something popular' but that is basically the case with Section 5. The wording is something like "likely to cause widespread offence or alarm" which means that the offence is defined in line with what the police or judges believe is the public mood. One example of this was that during COVID, a woman was murdered by an off duty police officer and there were protests in London during a lockdown. Many of the people at the protest were arrested (as had protested during anti-lockdown protest) but subsequently the police apologised and said they regretted what they did. There's no doubt they were implementing the law as written but they implemented it against a popular and sympathetic group - which didn't work out well.