What is the smallest offense that people should be sued over?

[FourKing Hell]

This question was inspired by Steve's zipper thread (link) . Everybody seemed to agree that an exchange of words (that may or may not have occured) was ground for a sexual harassment suit. My position is that it's ridiculous to sue somebody over a few words, however offensive. It's a waste of resources (lawyers, court costs etc.) no matter who pays. And should any financial compensation be awarded, this would be totally undeserved.

We've all heard the stories of ridiculous lawsuits. Hot coffee at McDonald's, dog in microwave, you name it. A lot are probably exaggerated or not true.

But the fact remains that, mostly in the US, people can and often will sue each other over everything. And often demanding staggering amounts of money as compensation.

What's your take on this? What's the 'minimum' that a person should be sued over?