Why? Every organization has whistleblowers. By the same token that Chelsea Manning leaked the state department cables, one can imagine a middle-tier operative with differing political ideology dropping a hint.
this is not clear. A sufficiently small organization needn't have whistleblowers. The extreme level of confidentially practiced in the relevant organizations ensures that the number of people privy to the knowledge and capable of leaking is very small.
Sure, it's definitely a possibility - but not a likely one. The people in charge of any such operation against Wikileaks would be particularly mindful of their own operatives leaking to WL itself.
There's no reason whatsoever to assume WL has any information about anything at any given time, unless they've publicly suggested that they have.
