In my home city of Cardiff, the police have started collecting people’s faces.

Innocent members of the public doing their Christmas shopping. Fans attending a football match. Demonstrators peacefully protesting outside an arms fair. In recent months, South Wales Police have deployed facial recognition technology on all of them, with no public consultation and no consent.

This intrusive new tech sees specialist surveillance cameras scan the faces of passers-by, making unique biometric maps of their features. These maps are then compared to and matched with images on bespoke police databases – which can come from social media.

I believe I’m one of the thousands of people who’ve had their faces scanned and stored.

The first time was last December, when I was walking down Queen Street among the crowds of Christmas shoppers – only to see a police van parked on the busy city centre road with a facial recognition camera on top. The force has given no explanation for why they were using such intrusive surveillance on such an ordinary day.

The second time was this March, when I attended a peaceful protest outside the Cardiff Arms Fair. South Wales Police parked a facial recognition van directly opposite our demonstration. It felt like a direct attempt to discourage us from using our legal right to protest.

The police are supposed to protect us and make us feel safe – but this technology does the opposite. It’s intimidating, disproportionate and dangerously inaccurate – and it undermines our rights.

There’s no law or guidance providing proper regulation of facial recognition. There’s no independent oversight of how it’s being used. Parliament hasn’t debated it. The public hasn’t been consulted. South Wales Police didn’t warn people before they rolled it out onto our streets.

But this technology has the potential to trample on the freedoms we take for granted. Having our faces indiscriminately scanned and stored by police as we go about our daily lives renders our privacy rights meaningless and places all of us in a perpetual police line-up.

When people know they are being watched and their personal information is being recorded by law enforcement officers, they change their behaviour. Some will feel scared to protest or express themselves freely – perfectly legal activities that they have every right to take part in. Activities that are crucial to keeping the UK a free, rights-respecting democracy.

And facial recognition doesn’t even help the police catch criminals. By their own admission, South Wales Police have used it at least 20 times since June 2015 – and 91 per cent of their ‘matches’ have been false. They’ve wrongly identified 2,451 people. The force stored their data for at least 31 days – even though they’d committed no crime.

Studies have shown facial recognition can also be discriminatory. The technology disproportionately misidentifies women and BAME people, meaning they are more likely to be wrongly stopped and questioned by police and to have their images stored.

Human rights organisation Liberty were invited to monitor the Metropolitan Police’s use of facial recognition at last year’s Notting Hill Carnival – and witnessed a young woman passing their cameras being ‘matched’ with a balding man on the force’s database.

I don’t think such potentially dangerous technology has any place on our streets. It is unlawful, discriminatory and frighteningly inaccurate. So, with the backing of Liberty, I’ve written to the Chief Constable of South Wales Police to demand they stop using facial recognition in public spaces. If they refuse, I’ll take them to court.

This is about more than protecting the freedom of the people of Cardiff. Police in London and Leicestershire have also used facial recognition technology – and it’s only a matter of time before forces across the country follow suit, unless we take a stand now.

In the UK we have policing by consent – which means Parliament and the public have a say over how our laws are enforced. As ever-more invasive technology with the potential to exert control over innocent people develops, it’s more important than ever that we’re consulted on the tools police use.

For more information on Ed’s campaign, visit his crowdfunding page here