I love to remind preachy folks like this, how many things AREN'T vegetarian. The processing/refining of white sugar can often be non-vegetarian. Dental anesthetic often isn't vegetarian. And some beers/wines aren't vegetarian. Anything "enriched with Omega-3" is just enriched with fish. True, the sugar refining process is getting away from use of bone char filters, and my neighborhood bar now has a vegan beer menu, but it's still very hard to lead an animal-free existence.

I'm not sure if I enjoy exposing a hypocrite more than seeing that "oh no" look on the pushy person's face when they learn how many beers are filtered.

Either way, unless I'm killing the cow in front of you on the plane, mind your own business. If you think you've got a right to lecture me, then I've got a right to tell you to stfu. Right after I tell you what's in your Omega 3 Orange Juice.