How can you tell if someone is a follower of the vegan philosophy?
They will constantly tell you about it
Hahaha, exactly right! They don't eat anything possibly made from an animal in their diets. I don't think I could do it.
I know, people who are vegan will not use any animal bi product. Even soaps that use animal products. 
Yeah, those are your "ethical vegans" and I think they're a bit more of the militant type with their philosophy.
Would they go as far as harming humans to protect animals and their vegan ways?
I doubt it. It's more the opposite. Nazi Germany was pretty heavy on the vegetarian persecution, or vegaphobia.
Oh wow, so would Nazi Germany harm people who ate only vegetables? 
Yep, but they're not the only ones. They've been persecuted as far back as the 3rd and 4th century, in ancient Greece. Can you believe that?
That is just crazy. Back in Bible times Cane murdered Able because he grew veggies instead of hunting meat.