Well, some vegans can be as annoying and pushy as those religious people who knock on doors, or scream on street corners.
Last time a Jehovah Witness knocked at my door we had a good chat, not about their way of life but he was from England like me. He sez he didn't like Canada, haha! what a fool, we talk about normal things. Another time I was downtown and a Hara Krishna devotee game me one of their magazines, so a day or so a JW knocked on my door, he gave me a Watchtower magazine and I told him to wait a moment and brought out the Krishna mag, haha! he ran away.
I knew (not personally) a fellow in Vancouver who would shout Bible stuff outside something like and Expo, he seemed cool, wasn't annoying.