It was started by a Seattle lawyer, Harish Bharti, a vegetarian Hindu who makes a habit out of identifying the ingredients in purportedly vegetarian foods. He examined McDonald's French fries. Back in 1990, news reports appeared that started for example, "McDonald's, Wendy's and Burger King are switching to all-vegetable oil to cook theft fries." The reason was to reduce the saturated fat content (bad for the heart), which, in McDonalds's case, went from 42 grams to 23 grams for a two-ounce serving of fries. Previously, the fries were cooked with beef tallow. Our on-line dictionary appetizingly defines tallow a, "Hard fat obtained from parts of the bodies of cattle, sheep or horses, and used in foodstuffs or to make candles, leather dressing, soap and lubricants." Yum.
The problem for McDonald's was that the veggie-oil cooked fries didn't taste like their popular tallow-cooked fries, which they solved by including a beef flavoring at the time of preprocessing for distribution (not while being cooked in the restaurant). Under the US government's food guidelines, they were allowed to label this beef flavoring as "natural flavor," which it is. But because of the hype over the switch to vegetable oil for frying, vegetarians assumed - and McDonald's did not try to dissuade - that the fries were now vegetarian.
Bharti sued McDonalds in 2001, and that grew into a class-action law suit involving a number of lawyers and organizations. Ultimately, Hindus, Sikhs, Jews, Muslims, vegetarians and vegans joined the fray - the Jews because the beef flavoring was not kosher and the Muslims because it wasn't halal.
In March, 2002, the lawsuit was close to being settled. McDonald's agreed to issue a formal apology, better disclosure of ingredients, creation of an advisory board and payment of US $10,000,000 to organizations which promote vegetarianism and issues related to the fries.
The apology reads, in part, "McDonald's sincerely apologizes to Hindus, vegetarians and others for failing to provide the kind of information they needed to make informed dietary decision at our U.S. restaurants. We acknowledge that, upon our switch to vegetable oil in the early 1990s for the purpose of reducing cholesterol, mistakes were made in communicating to the public and customers about ingredients in our French fries and hash browns. The mistakes included instances in which French fries and hash browns sold at U.S. restaurants were improperly identified as 'vegetarian.'"...