I was walking along the river in Warsaw in the afternoon and was approached by two men who claimed to be police. They showed me ID, but I have no idea what Polish policja ID is supposed to look like, much less how to tell if it was fake. They said they were checking for illegal substances.
I was suspicious because they weren't wearing uniforms and was kind of expecting them to rob me. In hindsight, I guess I should have asked if we could do this somewhere official, but nerves. Anyway, they asked for my ID, and one guy searched my pockets while the other guy was apparently copying down info from my ID. Nothing obviously bad happened, though whoever it was has my name/address/birthday/etc.
So, are plainclothes illegal substance 'stop-and-frisk' patrols a thing in Warsaw? Or were these guys more likely data-mining or otherwise planning to rob me?