I was in Toronto for a week, and I noticed that people honk all the time. It was mainly when the red light turned green and it was, no joke, 1 second that a person didn't move, someone would honk. Sometimes I heard two honks at one light. It was pretty funny, but surprising. No one was angry though.
I only honk if someone is really taking a long time, drifting into my lane or driving dangerously/wrong.
"Even a broken clock is right twice a day."