In case you really want to know:
The taxi-no-meter often park in front of big hotels, i.e. on Sukhumvit Road. They park always on the same spot, multiple cars. I notice these cars every day and the police should be able to see the same.
And I notice that lots of people look for taxis on busy streets like Sukhumvit. Taxis stop, the people talk to the driver, and then mostly the taxi drives away without people. Repeat that multiple times. And for many people. It's obvious what is going on.
And obviously the police know this. It seems they have some incentive to look the other way. Now what could that be...