Gangs wearing balaclavas are allegedly being used to protect Sadiq Khan's controversial Ulez cameras.
Residents in suburban London have reported the gang of "masked heavies" would often dress in black and hang around schools and homes while recording passersby on body cameras.
Ulez security guards were "roaming our streets on a daily basis", according to local residents.
A spokesperson from TFL said they hired "a small number of qualified security staff who are suitably licensed by the Security Industry Authority, due to ongoing criminal damage to Ulez cameras and vehicles.
Ulez cameras now guarded by masked guards as Sadiq Khan ramps up protection after vigilante attacks
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Mother-of-five Claire Dyer, 47, from Biggin Hill in Bromley told MailOnline: "You have thuggish security - they don't need to be behaving the way that they are.All you can see is their eyes. They are wearing masks and balaclavas - even that might have skeletons on them.
"Dressing all in black with body cameras all in masks. They seem to be above the law. They say they are a TFL representative but they don't actually work for TFL. It's such a grey area.
"Why are they trying to harass people? We are not aggressive or violent, just every day people. We are not hardened criminals. It feels like there has been a direct order to get us accused of something we haven't [done].
"We are not inner city London. We have elderly [people] who live in the area who now can't leave their homes. Sadiq Khan is very powerful. You are going up against powerful people and we are just normal citizens. We don't know what's going on."
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The scheme has proved controversial since it was expanded earlier this year
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Khan's actions have been slammed by Tories, who compared the Labour mayor's squads to masked highwayman Dick Turpin.
Leader of City Hall Conservatives Neil Garratt said: "Like Dick Turpin, Mayor Khan's modern day masked highwayman like to hide their faces.
"As they stand guard over his Ulez detector vans by schools and homes, these masked heavies make a menacing site in suburban London. Mr Khan rarely deigns to visit these parts, so his Ulez goon squad are now the face of his flagship vehicle toll, hitting outer London to raise cash for TfL, cash which we know he will spend somewhere else."
A TfL spokesperson said: 'Our security workers are directed not to wear face coverings unless they feel threatened by being closely filmed.
"Wearing of medical masks is permitted. We will remind our contractors of the situations when they can be worn. We have hired a small number of qualified security staff who are suitably licensed by the Security Industry Authority, due to ongoing criminal damage to Ulez cameras and vehicles.
The spokesperson added: "They are held to high standards of professionalism.
"Unfortunately, our contractors have been subjected to threats and abuse while carrying out their duties so they are advised to record any issues on body-worn cameras to deescalate conflict and if necessary, record evidence for police investigations.
"Vandalism is unacceptable and all incidents on our network are reported to the police for investigation.
"Criminal damage to Ulez cameras or vehicles puts the perpetrators at risk of prosecution and injury, while simultaneously risking the safety of the public."
Sadiq Khan declined to comment.