Those UK cameras don't work properly, they're illegal (cops ignored the law), & they don't recognise black people well enough.
In Ireland/EU & parts of America, there's plans to ban facial recogition tech for the foreseeable future.
In general, facial rec. tech can be gamed.
In taxi terms, I'm sure you've had 'hoodies' get a taxi from A to B and they put the hood back up when they get out of the taxi. I've even had wannabe gangsters (teenagers) put their hood up when they walk from the taxi to their front door! They'll just keep the hood up in the taxi or throw their baseball hat over the camera.
