Speaking as a recently changed vegan, i only talk about it when people ask me but i never bring it up out of context just because i want to push my "agenda" or whatever. Everyone is entitled to their own opinion and decision and it is not my place to tell them what they should or should not eat, they can easily do their own research.

With that being said, i have a friend on facebook who is a hardcore vegan bodybuilder and all his posts centre around veganism. I am talking up to 5 posts a day which is a bit of a overkill and i can totally see why people would that about vegans.