Check this out... A blogger did some research into whether the food that vegan
restaurants in LA were serving is really vegan and it turned out many tested
positive for dairy and/or egg. This has many implications for various people -
First of all, it impacts those of us who are kosher but eat at
non-kosher-certified vegan restaurants (though I'm sure even kosher-certified
vegan restaurants can have problems). Secondly it impacts those of us with egg
and/or dairy allergies. Thirdly, there are implications for vegans who choose to
abstain from putting animal products in their bodies. This brings up the issue
of sub-par or non-existent food labeling laws in some countries, too.

http://www.quarrygirl.com/2009/06/28/undercover-investigation-of-la-area-vegan-r\
estaurants/