What do Ponzi schemes, corrupt cops and organized-crime families have in common? They’ve all been taken down under the Racketeer Influenced and Corrupt Organizations (RICO) Act. This is a law that can result in enhanced criminal and civil penalties for acts performed as part of an ongoing criminal organization.

But the latest RICO defendants aren’t wiseguys from a real-life Club Ba-Da-Bing. They’re a handful of animal rights groups, their lawyers and a pay-for-play federal court witness.

Last month the owners of the popular Ringling Brothers circus filed a federal RICO lawsuit against the Humane Society of the United States, two of its lawyers, a Washington, D.C. law firm, and several other animal rights groups. The defendants are accused of committing bribery, fraud, obstruction of justice and money laundering, all in a nine-year scheme to prosecute a bogus elephant-abuse lawsuit against the circus.

These are pachyderm-sized charges. But the evidence is compelling. In December, federal Judge Emmet Sullivan dismissed the activists’ 2000 elephant suit, ruling that the plaintiffs paid more than $190,000 to a former Ringling elephant “barn helper” in exchange for his completely unreliable testimony.

The judge wrote that the animal rights groups, including the anti-circus Fund for Animals (which is now part of HSUS), cleverly disguised their payola through a nonprofit “wildlife advocacy” charity founded and operated by their lawyers. (These lawyers now have to find their own defense attorneys to deal with the RICO lawsuit.)

The primary purpose of these payments, says Judge Sullivan, was “to keep [the witness] involved with the litigation.” Judges tend to frown on paying witnesses what amounts to a secret retainer.

Anyone who’s seen a PETA protest up close will find it utterly unremarkable that animal activists would knowingly fudge the truth. But it’s telling that these groups would do just about anything — including buying themselves a federal court witness — to get their way.

The Ringling case (and its swift-justice RICO fallout) is just one piece of a disturbing trend of animal rights groups replacing public persuasion with courtroom strong-arm tactics.

Since the vegan firebrand Wayne Pacelle took the reins at HSUS in 2004, for instance, that organization has beefed-up its legal department ten-fold, from three lawyers to 30.

Why would the group behind those doe-eyed “save the puppies” TV infomercials need its own mid-sized law firm?

Because its leaders aim to completely remove things like livestock, lab mice and lambskin from society. One particularly efficient way to do that is to repeatedly sue your opponents.

In 2006, HSUS sued a New York duck farm that produced foie gras — not under an animal welfare law, but under the federal Clean Water Act. HSUS isn’t an environmental group. What was going on?

The animal rights group’s lawyers acted as though they cared deeply about the water quality of the Hudson River. But HSUS had also sued New York’s Empire State Development Corporation to stop it from helping that same duck farm upgrade and expand its water treatment facilities.

Catch the irony? Playing both sides of the environmental lawsuit game was really just a convenient way to bankrupt the farm, one of only a handful like it in America.

Animal rights lawyers are currently forced to conjure up creative ways to litigate, but that could soon change.

President Obama’s administration “regulatory czar” Cass Sunstein is a well-known proponent of the PETA-style view that animals should be permitted to sue people in court. In 2004, Sunstein wrote that “animals should be permitted to bring suit, with human beings as their representatives.”

That way lies madness. Just look at Switzerland, where pet owners can receive a court summons from an animal “counsel” for not giving their goldfish a proper companion, or for flushing it down the commode without first performing a state-sanctioned form of euthanasia.

Circus elephants certainly should not suffer abuse. But human activists also shouldn’t abuse the legal system in pursuit of fringe animal-liberation goals. Otherwise, it’s a short hop to replace the entire U.S. justice system with a kangaroo court.