Why is there no law regulating restaurants' and food processors' use of the word "vegetarian"?

I've never experienced this either, at least not with packaged foods. Restaurants are a whole different story. There are some areas in Europe where they have a vegan label but I'm not sure how well it is regulated. In the Eastern U.S., there is a grocery store (Wegmans) that uses a vegan label. They also have kosher, low cholesterol and other labels. I always read ingredients anyway, but I've never found anything they label as vegan to not be vegan. Oh, and goddamned Mexican restaurants...my worst restaurant experience ever was at a Mexican place.