Facial recognition: what it is and why you should care

Posted by Silkie Carlo on 23 August 2017

With the Met set to 'trial' controversial facial recognition technology at Notting Hill Carnival again, it's vital all attendees know what it is and why the plan must be scrapped. 

This weekend, the Metropolitan Police will deploy mobile facial recognition software to scan the faces of thousands of carnival-goers in Notting Hill.

Liberty and a coalition of civil liberties and race relations groups have called on the Met to scrap these plans – and we’re still hopeful they’ll see sense.

If they go ahead, it will make for a poisonous cocktail – a disregard for democratic scrutiny, a disavowal of the Met’s human rights obligations and an indifference to a serious risk of discrimination.

We’ll be there raising awareness and making sure attendees know their rights.

But what is facial recognition? And why is it so important we put the brakes on the creeping expansion of its use?

What is facial recognition?

Facial recognition is lightyears beyond regular CCTV – and it presents unique threats to our rights and freedoms.

It uses biometric software to create maps of people’s unique facial characteristics.

These are then measured and matched to images stored elsewhere.

And now law enforcement agencies are turning to this burgeoning industry.

We’ve seen facial recognition quietly rolled out at festivals and football matches in recent years – and just last week the Home Office announced plans to spend £5m more of taxpayers’ money on the software.

The ball is well and truly rolling – but without our say-so. We’ve had no public debate whatsoever about its use and no meaningful conversation about the major risks it poses.

No legal basis

Facial recognition exists in a vacuum – separate from other forms of camera surveillance and from other biometric data like fingerprints and DNA.

There is no law covering it. Our MPs have never debated it. We don’t even know if its use in public spaces could ever be lawful in a rights-respecting democracy.                                                                                                                        

The Government hasn’t published plans for its use and has missed its own deadline for producing a biometrics strategy – which would address facial recognition use – by four years.

Despite this, as the Met Police show, they’re ploughing on anyway. So much for policing by consent.

No oversight

There’s no independent oversight of the Met’s use of facial recognition. There is a Biometrics Commissioner – but it’s not in his remit. In short, it’s a blank cheque.

No transparency

We only know the Met is using facial recognition at the Carnival because Liberty asked them. Aside from that, the public has been told nothing about its use.

How long are your pictures – or those of your children – stored? Are they ever deleted?

What databases are they matched against? Are they linked to social media accounts, providing a treasure trove of information about you? Are they shared with anyone else?

Unless police tell us, we don’t even know when and where it’s used. We know nothing.

Inaccurate and racially biased

Essentially it’s a police identity parade on a monumental scale – but you don’t know you’re part of it. Which is all the more chilling given the serious questions around facial recognition’s accuracy.

The FBI’s software – which you’d imagine is fairly cutting edge – uses a facial recognition algorithm which misidentifies faces almost 15 per cent of the time – and is more likely to fail with women and black people.

We don’t know anything about the Met’s software. But, if it has similar flaws, the risks of using it anywhere – let alone at a celebration of Britain’s African Caribbean community – are clearly unacceptable.

When deployed at the Carnival last year, facial recognition cameras failed to identify anyone at all.

Before facial recognition is ‘trialled’ any further, we need a serious, meaningful conversation involving the public, Parliament, civil society and law enforcement. Until that happens, the Met needs to drop these plans.


  • If you see us at the Notting Hill Carnival, come and say hi and let us know your views. 
  • Similarly, if you are attending Carnival and are concerned about the Met's use of facial recognition technology, you can contact our legal department's Advice & Information team on advice@liberty-human-rights.org.uk.