
Well two people in England named George Dalmon and Andy Miles found out that sometimes All You Can Eat buffets have their limits. These guys have been going to the same restaurant for years and getting an average of 5 plates each visit. The owner finally had enough of their "greedy munching (mouching?)" and banned them from his establishment. This seems a little unfair. You will lose money on guys like George and Andy but you'll make it up on people like me.
Source: http://www.huffingtonpost.com/2012/10/02/banned-from-buffet-dalmon-miles_n_1933097.html