It’s been 25 years since California voters passed Proposition 65, a ballot initiative that required the state to maintain a list of “chemicals known to California to cause cancer or reproductive harm.”

The measure – the Safe Drinking Water and Toxics Enforcement Act of 1986 – was backed and supported by such Hollywood types as actress Jane Fonda and her then-husband, 1960s activist-turned-politician Tom Hayden. The list includes ubiquitous substances such as engine exhaust, which no one wants to breathe, but is impossible to avoid.

While Prop. 65’s intent was to protect Californians from carcinogens, the measure spawned a cottage industry of attorneys whose prey is California businesses (especially small retailers) and chemical manufacturers. In 2008, for instance, 199 lawsuits were settled, netting $14.6 million in legal fees and just $4.6 million in civil penalties.

Furthermore, two of these plaintiffs – the Center for Environmental Health and the Mateel Environmental Justice Foundation – accounted for 76 of those lawsuits, according the California Attorney General’s Office.

Here’s how filing a lawsuit works: Prop. 65 attorneys find a business where people may be exposed to a substance on the list. They send a required “notice of violation,” giving them the right to sue. After 60 days, they file a complaint on behalf of a straw plaintiff. Knowing successful litigation requires expensive affirmative defenses, the business buys its peace by paying the plaintiff’s inflated attorney’s fees. A judgment is entered that the business hopes will prevent future lawsuits by other “professional plaintiffs” and “bounty hunters.”

Another sign goes up in California: “WARNING: This area contains a chemical known to the State of California to cause cancer.” The plaintiff issues a news release claiming to have “protected” Californians, and asks for donations to support further litigation.

This abuse of Prop. 65 sparked a stiff rebuke from a California Appellate Court in 2006. The court noted that Prop. 65 bounty-hunter action is so “absurdly easy” that the attorneys’ fees paid by defendants to avoid litigation are “objectively unconscionable.”

Around that same time then-California Attorney General Jerry Brown sent a letter to one bounty hunter, stating: “Your clients have collected significant sums of money from businesses that have little or no liability for past violations, and an amount of attorney fees that appears to exceed a reasonable amount.”

The Attorney General’s Office requires that people who file Prop. 65 lawsuits first inform the A.G.’s office as well as give it the final results of the court action after the case is settled.