The Twitterati (and presumably a bevy of bankers) went astir today after a small DC watchdog began systematically leaking millions of financial secrets about offshore companies. Here's why you should care.

What is this "Offshore Leaks" thing everyone's freaking out about?

For 15 months, nearly 100 reporters from outlets around the world have worked together to analyze a trove of 2.5 million documents detailing the identities and activities of 120,000 offshore companies, most of them based in the Caymans and the British Virgin Islands. In terms of sheer data, that's 160 times larger than Wikileaks' cache of US embassy cables.

The project, billed by its organizer as the "likely largest journalism collaboration in history," shines a light on the tactics wealthy individuals and businesses use to avoid taxes, run Ponzi-style schemes, and participate in corrupt government and banking practices. It was all put together by the International Center for Investigative Journalists, a project run by the DC-based nonprofit Center for Public Integrity aimed at "exposing hidden dealings of politicians, con artists, and the mega-rich in more than 170 countries."

I've never understood how offshore tax havens work. Is there a simple breakdown?

Glad you asked. Canada-based CBC News has a great interactive explanation that walks you through the process of sheltering your cash in a variety of tropical environs. Give it a try.

Okay, but where'd these journos get all their info from?

According to the Guardian, one of ICIJ's partner media outlets, the load of docs came into the nonprofit from a variety of sources, including confidential informants. The linchpin for these info-gathering efforts appears to be ICIJ director Gerard Ryle, an Australian investigative reporter who blew the lid off an international fraudster whose umbrella corporation was headquartered in the British Virgin Islands.

So who's publishing what?

In Wikileaks fashion, ICIJ has been sharing links to journos' stories on Twitter with the hashtag #offshoreleaks. Much of what ICIJ's partners have published so far mirrors the exhaustive information on the nonprofit's site.

The Washington Post has yet to roll out its much-anticipated analysis of the offshore info, which will presumably include details on the Americans implicated by the leaked documents. Most of the other partners—CBC in Canada, Guardian in the UK, Spiegel in Germany—have focused on companies and private citizens in their nations who've stashed money in the Caribbean. Here's a map of the open investigations worldwide; it's a safe bet that each media organization will publish more reporting on the documents.

Okay, but where's the dirt, and what's the likely impact?

Well, we sure wouldn't want to be the deputy speaker of the Mongolian parliament today. (He may have to resign after the project exposed $1 million he'd secreted in a Swiss account while he was the nation's finance minister.) But beyond that, here are some of the folks who've been called out so far:

Ferdinand Marcos' oldest daughter Imee, who may have hidden some of the $5 billion her father sucked from state coffers as president of the Philippines.

Principals of several companies with deep military and intelligence connections, including the arms producer BAE and the cyber-surveillance firm Gamma Group, which provided spy software to Hosni Mubarak's Egyptian regime. The offshore entities reportedly were used "to distribute hundreds of millions of pounds in secret payments to get overseas arms contracts."

A Canadian senator's husband, who moved $1.1 million offshore in the midst of a national tax dispute; the president of Azerbaijan, who had a mogul secretly create offshore accounts for his adolescent daughters, possibly against the law; and damn near everyone in the Russian government and state-run industries—from managers of the natural-gas conglomerate Gazprom to a top aide of Vladimir Putin whose offshore fortune has helped bankroll an investor in Facebook and Groupon.

Four thousand US-born investors, including Denise Rich, who's written songs for Celine Dion and Mandy Moore—and was married to disgraced financier (and recipient of a Bill Clinton pardon) Marc Rich. Denise Rich reportedly kept $144 million in a Cook Islands trust in the mid-2000s...five years before she renounced her US citizenship and moved to tax-friendly Austria.

If you used offshore entities to shelter your income, art collection, yacht fleet, and vast land titles, you, too, could be hearing from some reporters soon.

So we'll finally know what Mitt Romney and his brood are worth?

Well, shit, man. Been there, done that. But yeah, perhaps the new files can add to our already-robust understanding of the Romney family offshore holdings.

What about Gawker Media, or its owner Nick Denton?

Pardon me?

So, like, in the name of financial transparency: Who funded this project?

With dozens of media organizations around the world participating in this document sift, it's a pretty safe bet that some of their owners will pop up in the offshore data themselves. The Guardian points out that even its parent company "has used offshore entities to acquire other companies"—though not in the shadow of darkness that persists among high-rolling financiers and trust-funders in the islands.

ICIJ's parent, the Center for Public Integrity, lists its funders here. Will any of them pop up in the documents? Man, that would be: Awk. Ward. We're looking into it.

[Image by Jim Cooke]