This happened a long time ago, but I was reminded of it again recently.
It was my first year living in St. Petersburg. My friend (also American) and I were riding the bus. As usual I flashed my all-purpose paper bus pass at the conductor. In those days, the conductor didn't have an electronic wand to check passes. But sometimes a "controller" would get on the bus with an instrument that he could use to scan your documents and take disciplinary action if necessary.
I obediently showed him my paper pass.
"Blah blah blah" he said. I guess my Russian wasn't very good at that time.
"Show him your electronic card," my friend said. I took out my electronic metro pass that accompanies the bus pass. +/-