I got asked in Kanchanaburi, there was a gang of immigration all dressed up in their SWAT style uniforms randomly harassing tourists. around the River Kwai bridge. I was with my friend from the UK who was over for a short trip. They basically surrounded us, asked to see our passports, were told they were at the hotel and I showed them photos of mine (my friend didn't have photos) so they started talking about escorting her back to the hotel. Managed to talk them around to not doing that, and that was after they quizzed me about what counter at Changwattana deals with my kind of extension. It was a complete farce and my friend just said, 'WTF was that about?' after. Oh, and the cherry on the cake, they wanted a photo with us after, all smiles and look what a great job we are doing.
So, it ain't just in Pattaya that this clown show happens.