Of all the injustices crying out to be righted, slack fill ranks pretty low. But that hasn't stopped plaintiffs lawyers from bringing a flurry of cases against food and drug companies for under-filling their packaging, leaving empty, non-functional “slack fill” space.

The suits—which, according to a report by the U.S. Chamber Institute for Legal Reform, are proliferating—are premised on a rather unattractive assumption: people are dumb. If a box is big, you'll automatically think you're getting more of whatever it is you're buying, never mind what the label says.

Sorry, but I have zero sympathy for a grown-up who buys a bottle of Advil that clearly says it contains, say, 48 pills, and then sues because it's not filled to the brim. A federal judge in New York was right-on to toss that suit last year, handing an easy win to Skadden, Arps, Slate, Meagher & Flom.