To add: same happened in russia around 2018 on a couple of subway stations in St.-Pete and in moscow at first
the result? faster tracking and arrests of people for checks who were deemed too problematic + (i.e. with anti-war protests in 2022) the cameras were used to track or threat tracking almost everyone who protested, and lowering the load on the police by coming to the dwellings afterwards in the next several days or even weeks without the need to do it there and then
in 2018-2021 it was still possible to overwhelm the holding capacity of jails in major cities, but after mass tracking it more or less became obsolete
the result? faster tracking and arrests of people for checks who were deemed too problematic + (i.e. with anti-war protests in 2022) the cameras were used to track or threat tracking almost everyone who protested, and lowering the load on the police by coming to the dwellings afterwards in the next several days or even weeks without the need to do it there and then
in 2018-2021 it was still possible to overwhelm the holding capacity of jails in major cities, but after mass tracking it more or less became obsolete