It looks like a pretty bleak bus stop with all the barbed wire on the fence behind...almost gives the feeling of being outside a prison.
The ad is for a Canadian clothing company, Bench, but someone has stuck an announcement on it with a warning about a certain type of drug: "Are you taking a Benzodiazepine sleeping pill,tranquilizer or z-drug? Learn the devastating truth. Go to Benzo.Org.UK." The site warns of easy addiction to the drug and over-prescription by doctors. The kids in the poster looked pretty zonked out, which is what perhaps prompted the posting of the warning at this particular place, although the Benzo UK web page mostly describes middle-aged and elderly people as being addicted to sleeping pills.
Sounds a bit of a nightmare.