SOME lawmen chase villains down mean streets. Others chase fraudsters across balance-sheets. In the stomach-churning stench of the Vetport at John F. Kennedy International Airport, yet others don surgical masks, goggles and rubber gloves, and peer with penlights into crates holding thousands of little birds.

These inspectors with the Fish and Wildlife Service (FWS) examine not just live animals entering America—such as the 45 outlaw jays they found lurking in a legal shipment of thousands of birds—but plants and animal products such as handbags and caviar. In 2011 FWS agents raided Gibson Guitar facilities in Tennessee and seized wood worth hundreds of thousands of dollars that they suspected had been illegally imported from India and Madagascar.

The buyers may be besotted ornithophiles, air-brained fashionistas or greedy gourmets. But the sellers are crooks, supplying a market which, according to America’s Congressional Research Service, is worth as much as $133 billion annually. Commodities such as rhino horn and caviar offer criminals two benefits rarely found together: high prices and low risk. Rhino horn can fetch up to $50,000 per kilogram, more than gold or the American street value of cocaine. Get caught bringing a kilogram of cocaine into America and you could face 40 years in prison and a $5m fine. On January 10th, by contrast, a New York court sentenced a rhino-horn trafficker to just 14 months.

The appeal of such trade is increased, however unwittingly, by governments trying harder to protect what is precious and rare. “When we finally get it together to agree that we’ll only take ten tuna out of the water this year because that’s all we can afford to take, that 11th tuna will be worth a lot of money,” says Theodore Leggett of the UN Office on Drugs and Crime (UNODC). As with tuna, so with ebony, ivory and rhino horn—all being regulated more tightly, and all still desirable.

The world is their oyster

Organised crime is globalising and diversifying. Mono-ethnic, hierarchical mafias are being replaced by multi-ethnic networks that operate across borders and commit many types of offence. In an ongoing investigation into rhino-horn trafficking, the FWS arrested Irish travellers using indigent Texans to procure material for Chinese and Vietnamese buyers. Europol, the European Union’s law-enforcement agency, estimates that just a quarter of Europe’s roughly 3,600 organised-crime groups have a main nationality, and that some operate in dozens of countries. A third are involved in more than one criminal enterprise, with half of those linked to drug-trafficking.

And though traditional trafficking in drugs, guns and people is still lucrative, gangs are increasingly moving into lower-risk, higher-reward areas—not just wildlife, but fraud and illegal waste-disposal. The UNODC says the value of cross-border trade in counterfeit goods could be as much as $250 billion a year. On January 14th it launched a campaign to tell consumers about the dangers posed by fake electronics, food, medicines and the like—and how the buyers of knock-offs enrich some highly unpleasant people.

Gangs in Britain make around £9 billion ($14.8 billion) a year from tax, benefit, excise-duty and other fraud—not much less than the £11 billion they earn from drugs. In America cigarette-trafficking deprives state, local and federal governments of $5 billion in tax revenues annually. The European Union estimates that losses within its borders from cigarette smuggling, tax fraud and false claims on its funds by organised groups total €34 billion ($46.5 billion) a year. But member states bring fewer than ten cases each a year for defrauding the EU, and sentences tend to be light.

According to the FLARE Network, an international group of campaigners against organised crime, criminal groups in Italy make around €14 billion a year from being mixed up in agriculture. In some parts of the country mafias control food production and distribution; Franco La Torre, FLARE’s president, says they also enrich themselves through fraudulent claims on EU agricultural funds. Increasingly strict regulation of waste disposal has created another profitable opportunity for organised crime in Europe—particularly, according to Europol, for the Italian Camorra, ’Ndrangheta and Cosa Nostra.

Where politics is corrupt and law enforcement weak, as in much of Latin America, gangsters still look much as they have for decades: brutal and keen on the brand-enhancing effect of highly visible violence. But in the rich world, the shift to new lines of business is changing the face of organised crime. The FBI estimates that the four big Italian Mafia groups still have 3,000 members and affiliates in America. But as traditional industries have shrivelled so, too, have the unions and tight-knit neighbourhoods that were once their fertile breeding grounds.

Old-style loan sharks and drug-dealers are finding a new role as distributors for the modern mobsters who manage the supply chains, marketing, finance and human resources needed to move goods, money and people across borders. “The new generation are very talented businessmen and technologically advanced experts,” says Mr La Torre. They prefer invisibility to showy violence. Many also have legitimate business interests.

Clever criminals acting across borders are extremely difficult to prosecute. They profit from gaps in enforcement and regulation, and conceal their illegal acts in complex supply chains. If a network of Nigerian scammers based in Amsterdam defrauds French, Australian and American credit-card holders, where does the crime occur? And who has the motivation, not to mention the jurisdiction, to prosecute?

A commodity such as oil, ivory or fish will be transported on a ship flying a flag of convenience, explains Mr Leggett. The ship will be owned by a holding company registered in a tax haven with a phoney board. Thus the criminals can disguise the provenance of their ill-gotten goods and middlemen can plead ignorance.

Governments are reacting by getting law-enforcement agencies to work together. America is trying to improve the flow of information between them. Britain’s recently created National Crime Agency will have the power to order local police forces to make arrests, unlike the body it replaced. Europol analyses and distributes information from EU member states.

But organised crime sells things that people want—not just drugs and sex, but handbags, sushi and wardrobes, too. Businesses and consumers will have to accept, says Mr Leggett, “that there is no such thing as just wood. It has to be wood from somewhere.” And they will have to agree not to sell or buy illegally harvested wood, however beautiful or cheap.

Until then, illicit goods will keep coming in quantities too great for governments to stop. One FWS inspector estimates that for all the peering, prodding and chirping, for all the rewards promised and rhino-horn traffickers caught, the agency picks up perhaps 5% of wildlife brought illicitly into America. For criminals, that is merely a light tax on the profits from the rest.