What constitutes a "public nuisance" is obviously very hard to define. If it were easy, we wouldn't have much to write about.

Taking the term literally, you should be able to sue anyone who walks on the left side of the aisle in grocery stores. You're in public, they're a nuisance. They don't understand that in order to have a system that will allow everyone to walk comfortably through the store they need to adopt the same rules that work so well on roads -- stay to the right, look both ways before entering a new road.

It's a slam-dunk case, in my book. Rhode Island Superior Court Judge Michael Silverstein apparently would agree.

But have companies that manufactured lead paint (when it was legal more than 30 years ago) caused a public nuisance because that same paint (now found to be toxic) is coming off buildings and kids are eating it?

The Manhattan Institute's Center for Legal Policy seemed to be celebrating recent victories by paint companies in Missouri, Ohio, New Jersey and Wisconsin when it released its report today on the state of lead paint litigation.

If you're a regular at this site, you already know the story: Plaintiffs firm Motley Rice decided to take on the paint industry by using a nuisance claim to work around the now-expired statute of limitations a products liability claim would be susceptible to, then recruited Rhode Island as its testing ground. Currently, that case has held three companies liable (thanks to Silverstein instructing the jury to do so) and will later be heard by the state's Supreme Court.

Now, since the companies' victories in the other states, pro-business groups are becoming a little more confident in this country's civil justice system. If this were a minor league baseball game, they'd be playing that "Celebrate good times.. Come on!" song.

But a warning to those in attendance: They don't play the celebration music after the fourth batter of the game grounds out to end the first inning. There are a lot of states out there, and Motley Rice just needs that victory in Rhode Island to take its show on a few more roads.

Take West Virginia, for instance. A public nuisance claim against Purdue Pharma helped coax a $10 million settlement when Attorney General Darrell McGraw got ticked that the state had to spend (mostly federal) Medicaid dollars treating people who bought OxyContin on the black market.

Why McGraw hasn't filed a nuisance claim against the paint companies is beyond me. Everything is in place, even a sometimes-bullheaded Supreme Court that recently ignored a precedent accepted by nearly every other state when making its own decision and, as you see in this 1992 opinion, has admitted there is no precise definition of the term "nuisance."

You can't help get the feeling that Connecticut could be a target, too, considering Attorney General Richard Blumenthal, I've been told, is the most celebrated political figure in the state. Another fight for the "little guy" would do wonders for his coming run at Governor.

Mississippi's Jim Hood has made his name this year fighting insurance companies for hurricane victims. Whether or not his legal arguments are correct doesn't change the fact that it is a beautiful public relations move, and a jury of those victims will probably agree with him on just about anything.

And the list of prospective states goes on and on. Pro-business groups that release reports celebrating what they call "common sense rulings" against the nuisance claims should probably put the celebration music on pause. They might find out that their definitions of "common sense" and "public nuisance" aren't accepted everywhere.