Fast Food Fails (PHOTOS)

From scathing documentaries to PETA protests to restrictive regulations and legislation, crackdowns on fast food are a way of life for junk food industry giants, highlighting the danger of consumers' increasing appetite for their greasy, high-calorie food. But the shortcomings of McDonalds, Dunkin' Donuts and other fast food favorites aren't limited to high-profile problems like obesity. As we can see from the number of fast food FAIL pics that customers have posted online over the years, the industry's problems begin on a much smaller -- and funnier -- scale.

We've rounded up some of our favorite fast food FAILS from around the web, including some of the most ridiculous signs we've ever seen, in the slideshow below. We think you'll agree that some are much more unforgivable than others. Vote for the biggest FAIL!