Lawyers for product manufacturers now fear clients are liable for up to $500 for every tube of mascara or box of garbage bags marked with an expired patent—an error that turns out to be quite common.

The working stiffs and the old Dutch families had joined with the lawyers and doctors to battle a common nemesis whose garish sign would savage property values.

A common scenario in these cases is that a small business adopts a quirky knock-off of a bigger, more famous company's brand, prompting cease-and-desist letters from the big-company's lawyers.