Using Technology to Protect Anonymous Sources?
No technological countermeasures are going to keep a source's identity from being known to the reporter himself, and for that reporter a refusal to testify could be damning. It wouldn't be difficult, however, to set up a system to circumvent court orders to turn over documents or files.
A previous poster mentioned serving the data from offshore. This is a good start, but there's nothing to stop a court from ordering you to access the data and turn it over. Better would be for the EFF, perhaps, and a consortium of newspapers to hire an attorney to watch over the data and give him discretion to withhold it from the owners of the data. Having an explicit agreement to turn over the data could be construed, perhaps, as obstructing justice before the fact (which would be an interesting case to try), but trusting the host's judgement with a wink and a nod could solve a lot of issues. As long as you have control over the data, it's your ass on the line. As soon as you relinquish it, it's somebody else's problem. And if that somebody else is out of the jurisdiction, it's nobody's problem.