I had one two days ago, in Pattaya. I was driving my motorbike alone in the evening, when two police officers on a bike came up on the side and told me to stop. No erratic driving from my side, just normal driving. Same questions, starting with searching my pockets (without consent), and my bike. Clearly looking for drugs (never done drugs in my life). After not finding anything, they wanted to see my passport, and my visa. Asked if I had overstay. Showed them a copy on my phone. No questions about why I didn't carry my actual pp, because that is not needed. A copy is always sufficient. After checking it all, I was "free to go". Didn't think about it at the time, but if they wanted to place drugs on me, or "find" drugs on my bike, they certainly could have done so. But I may be naive, and think better of the police than that. Maybe they were hoping to get a payment at late night, if I had something to hide?