McDonald's argued that the Irish fast food chain "Supermac's" had copied the name of their infamous "Big Mac," a popular menu item in the fast food giant. It turns out Supermac's didn't even have a menu item named the Big Mac, and as a result of the lawsuit regulators have stripped McDonald's of its trademark on the name altogether in the EU. Now, the name can be used by anyone within the EU without fear of repercussion from McDonald's.
Regulators say that McDonald's hadn't been able to prove genuine use of the name in over five years. The fast food company had used the similarity between the name "Big Mac" and "Supermac's" to block the expansion of the Irish chain.
McDonald's doesn't typically lose these cases. In 1993, they won a landmark case against a New York dentist who asked for a trademark on the name "McDental."