Let's look at it from Wikileaks' point of view: Would Wikileaks want to use your (or any) SaaS, given the potential risks to them? Much of their data is very sensitive, so why would they risk compromising their data by passing it through an untrusted third-party service?
For example, Wikileaks may have received documents that reveal the true identities of people who could be killed if their identities were known. They wouldn't want such documents to be seen before they had a chance to redact them. Some documents may be considered too sensitive to ever release to the public, even in redacted form. Why should they trust you with this sensitive information? Would you be able to protect this information from the various intelligence agencies around the world who might be interested in getting it (which could involve compromising you to get at it)?