I dunno, I can understand this... I know some fairly militant vegetarians, of the punk and hippie variety. I could see several of them ending up homeless at some point (they live fairly bohemian lifestyles to begin with, and I know several who have, over certain periods, squatted in abandoned buildings), and I doubt they would give up their principles for that reason. Of course, most of them are resourceful enough that they'd dumpster-dive for food (restaurants and supermarkets throw away all sorts of perfectly edible food), so if they were to beg, it would more likely be for something other than food (saving up for a sleeping bag, maybe?), but that probably doesn't go over well when you're panhandling...