WikiLeaks, the Sweden-based organisation that publishes anonymous leaks of secret material (most recently 90,000 documents about the War in Afghanistan) has until now, relied on donations to fund its activities. That’s lead to outages when funds became scarce, for whatever reason. But today WikiLeaks is unleashing a potentially devastating strike against criitics which could see it become an almost unstoppable force in the world’s media. It’s joined Flattr.

Flattr is another Sweden-based outfit with close links to The Pirate Bay as the the brainchild of a group of people formerly associated with The [infamous] Pirate Bay, including Peter Sunde. Flattr has a micropayments business model based on the idea of people tipping content they like, Digg or perhaps Facebook Like buttons – but this time with real money. As a result, WikiLeaks Afghan War Diary, which has made headlnes around the world, is currently pulling in hundreds of Flattrs, with most of them anonymous. We covered Flattr’s launch in July.

Users can “Flattr” content by setting up a Flattr account which sets a a monthly fee — a minimum €2 — that they are willing to contribute for any kind of online content. When the user finds something they like that has a Flattr button, they can click the button to “reward” the content provider. At the end of the month, the user’s monthly fee is split equally among the holders of the content that they “flattered”. Although Flattr is currently in beta and an invite is required to set up an account it is already in use by two major German newspapers, completely unprompted: taz.de and Freitag.de.

Sunde told me on the phone that they are aiming for a full open beta launch in around two weeks and he is “prepared for the controversy” surrounding the WikiLeaks partnership.

But with Flattr backed by investors from the UK’s White Bear Yard and expected to grow virally in the next few months, WikiLeaks just got a sustainable model which will further fund their activities.

The history of WikiLeaks’ operation suggests it had to find a new source of funds. On 24 December 2009 it announced a shortage of funds and suspended its site, and only achieved a minimum fundraising goal by early February 2010. On 22 January 2010, PayPal suspended Wikileaks’ donation account and froze its assets but the account was restored three days later.

But it’s clear WikiLeaks no longer plans to rely on one-off donations.

By marrying its controversial content with the simple ability for people anywhere on the web to make micro donations it could well have hit on an unstoppable model.