McD's got sued because their coffee was too hot. McD's kept the coffee near boiling even though they had numerous complaints about the coffee being too hot and causing burns. They ignored the complaints even though they knew people were getting hurt.
WHY did McD's keep the coffee at near boiling?
Because they allowed free refills on coffee. To save money, by minimizing refills, they kept the coffee as hot as possible.
The person who sued had THIRD degree burns that required skin grafts.
Ironically about the time this lady was burned I was in McD's getting coffee just before going to WDW. I sipped the coffee which burned my lip and tongue.

I waited for the coffee to cool down and ended up getting a cup of ice to make it cool enough to drink. But by that time I was done eating.
There are plenty of articles on the web regarding what McD's fault in the matter.
At the time there were two other lawsuits I heard about, both with psychics that were indeed frivolous. One of the psychics got an MRI or CAT scan which removed her psychic ability so she sued the Doc/hospital. The other psychic lost his/her powers when on the ski slope. She/he had an accident with another skier which removed the psychic abilities from the psychic.
You would have thought the psychics would have seen this coming....
Later,
Dan