Count me among those who thought that RAM lost its contents reliably when it was unpowered. On this basis, I thought that a stolen computer with an encrypted swap file and encrypted home folders ought to be reasonably useless to data-thieves.
Except, it seems that it isn’t true. The gory details are here, courtousy of a group at Princeton University, who claim to be able to hack many forms of hard-disk encryption with little or no exotic technology.
The video is well worth watching, and the research paper itself remarkably readable.