I remembered an ad on the subway I saw just last year. While trying to look for it I saw a subway ad about etiquette on the subway. I believe this ad came out three years ago, in 2009. The pictures are pretty self-explanatory.
I don’t see the ad often anymore. Nowadays, what I most see is the ad about using headphones or earphones with MP3 players, cellphones, PMP and other gadgets. They also have an announcement now about not talking loudly on the subway when taking a call.