The tourists are not objecting to safety patrols, nobody is, its great they are doing it.
The tourists are 'objecting' to being hassled by immigration whilst they are doing nothing wrong having a good time? Now certainly there may be a few folks there on overstay, but is this the right way of going about it? Real tourists are not the main problem regarding overstay?
I think its a just a PR stunt to show they are doing something?
On their database in immigration they must know who is on overstay, a simple search would bring up the perps and if they were living in Thailand as opposed to being a tourist they would have an address, TM30? Why dont they raid all these addressees, sure some may be a false address, but only one way to find out? Or have the police no interest in catching the 'real criminals'?