I took a detour home a few days ago and ended up in Canary Wharf. On my way out of the station, I noticed there was a door leading into a public toilet just past the ticket machines. In I went and discovered a fairly large toilet. Three urinals with three guys standing as if they were pissing. I went into a cubicle, and when I came out they were still there. Clearly something going on, especially when a suspicious character walked in and wandered into one of the cubicles as if he meant to wait around for an empty urinal.
So, now you know: Canary Wharf is worth checking out at rush hour.