Mr. Koppell, the New York Attorney General, estimated that all told his office had a backlog of 28,000 prisoner lawsuits.

He favors improving the screening of prisoner lawsuits or placing some restrictions on their ability to file suit.

The question is whether guards who work for private companies that run prisons have the same shield against prisoner lawsuits as guards who work for public prison agencies.

There are many frivolous claims, but those in responsible positions ought not to ridicule all prisoner lawsuits by perpetuating myths about them.

To measure the effectiveness of imprisonment in reducing crimes, Professor Levitt has studied the results of successful prisoner lawsuits to reduce overcrowding.

Given all the complaints about frivolous prisoner lawsuits, this new rule may sound appealing.

And it apparently authorized prisoner lawsuits to recover damages.

On Monday, the Supreme Court ruled unanimously that a federal appeals court had overstepped its bounds by making prisoner lawsuits even harder to file than Congress intended.

The office is considering requests to mediate prisoner lawsuits against corrections officers and to train students to act as mediators for their classmates.

But it is often hard to tell at first blush which prisoner lawsuits are meritorious and which will prove ridiculous.