For a really good -albeit long- read, check out this October, 2002 article by Jeffrey Goldberger that appeared in the New Yorker
The Wild West
It covers the triple-frontier area between Paraguay, Brazil and Argentina, which is possibly one of the wildest and most fascinating places for shopping. You can buy anything from legitimate electronics at good prices, stolen vehicles, weapons, counterfeit goods. And all sorts of shady activities, like money laundering. It is also where Hizbullah raises funds directly and through illegal activities, and where it has a big network in place. The anti-Jewish attacks on Argentina are alleged to have been planned from there.
A decaying iron bridge, the International Friendship Bridge, connects Foz do Iguaçu to its Paraguayan sister city, Ciudad del Este, the City of the East. Ciudad del Este is at the heart of the zone known as the Triple Frontier, the point where Paraguay, Brazil, and Argentina meet, which has served for nearly thirty years as a hospitable base of operations for smugglers, counterfeiters, and tax dodgers. The Triple Frontier has earned its reputation as one of the most lawless places in the world. Now, it is believed, the Frontier is also the center of Middle Eastern terrorism in South America.
Roughly two hundred thousand people live in the Ciudad del Este region, including a substantial minority of Arab Muslims; in the Triple Frontier zone, there may be as many as thirty thousand. According to intelligence officials in the region and in Washington, this Muslim community has in its midst a hard core of terrorists, many of them associated with Hezbollah, the Lebanese Shiite group backed by the Iranian government; some with Hamas, the Palestinian fundamentalist group; and some with Al Qaeda. It is, over all, a community under the influence of extreme Islamic beliefs; intelligence officials told me that some of the Triple Frontier Arabs held celebrations on September 11th of last year and also on the anniversary this year. These officials said that Hezbollah runs weekend training camps on farms cut out of the rain forest of the Triple Frontier. In at least one of these camps, in the remote jungle terrain near Foz do Iguaçu, young adults get weapons training and children are indoctrinated in Hezbollah ideology—a mixture of anti-American and anti-Jewish views inspired by Ayatollah Khomeini.
In the Triple Frontier, Hezbollah raises money from legitimate businesses but, more frequently, from illicit activities, ranging from drug smuggling to the pirating of compact disks. Unlike the other radical Islamic groups in the Triple Frontier, Hezbollah, it is said, has the capability to commit acts of terror.
The rest of the article also discusses fundraising activities in the United States