I often wonder about vegans.
It is possible that they are right that eating animals (or any animal products) may be causing undue harm, or that the line is so unclear that we should err on the side of caution.
Here are some issues with that.
Honey Bees and their domestication lead directly to most of the available plants that we eat. Removing them would essentially cause a food crisis for millions of people.
If we were to all stop eating meat this instant (and never do so again) we have the problem of what to do with all of the domestic animals. There are far to many to release into the wild, plus most of them are so domesticated that they wouldn't survive. Not to mention that they are invasive and would completely disrupt any ecosystem through sheer volume. The options here appear to be either a slow phasing out of eating animals (in which case, calm down about my organic goat cheese) or a quick and painless slaughter of (nearly) all domesticated animals (OMGBBQ?). In some cases this would effectively wipe out the species (there aren't any Aurochs left after all).
Scale problem. If vegans are worried about the suffering of conscious creatures, they should be doing what they can to eliminate it in humans first. This would include getting more domestic animals to some places (and less to others). After which they should concentrate on the other apes, cetaceans, and onward down the line of neural complexity.
If vegans are claiming health reasons, they should focus on promoting vaccination and exercise and well as portioning control and meal planning. This version can actually coincide with the type of whole food/ organic only attitude they often exhibit. Locally in the US they should concentrate on getting farm subsidies removed from corn and other low nutrition crops and added to crop variety to try and make the price of "healthy foods" competitive on shelves for families. Also B vitamins, need I say more?
So if a vegan gives you a hard time about your animal products, especially if they are conscientiously purchased, remember that they are probably a hypocrite that hasn't actually addressed the real problems of their world view. Most world views are a filter to allow you to not address issues rather than one to let you find an issue. So before you try to wipe the smug condensation off of their annoying face, ask if you are simply filtering out actual conversation.