The first legal battle in the UK over police use of facial recognition technology will begin later.
Ed Bridges has crowdfunded action against South Wales Police over claims that the use of the technology on him was an unlawful violation of privacy.
He will also argue it breaches data protection and equality laws during a three-day hearing at Cardiff Civil Justice and Family Centre.
Facial recognition technology maps faces in a crowd then compares results with a "watch list" of images which can include suspects, missing people and persons of interest.
Police who have trialled the technology hope it can help tackle crime but campaigners argue it breaches privacy and civil liberty.
South Wales Police first used Automatic Facial Recognition (AFR) during the Champions League final week in Cardiff in 2017. Mr Bridges, from Cardiff, said he has been scanned by AFR at least twice, including at a peaceful anti-arms protest and while doing Christmas shopping, according to the the campaign group Liberty, which represents him.
Liberty claims South Wales Police have used facial recognition technology "on around 50 occasions".
The force said it would not comment until the judicial review is finished.
The Metropolitan Police have also trialled the technology several times in London.
Information about AFR on a website set up by South Wales Police says it will help the force "become smarter" and make its patch safer.
The force has said it works to "ensure that the deployment of this technology is proportionate whilst recognising the need to balance security and privacy".
Liberty said freedom of information requests have shown that South Wales Police's use of live AFR technology "resulted in 'true matches' with less than 9% accuracy" in the first year.