Online storage -- but on other users' HDs

Wuala is a new concept in online storage where you essentially have your stuff, in an encrypted form, stored on other (non-server) computers around the world.
This does make me a bit nervous but I'm willing to give it a try as I never like to shy away from new concepts (at least, from those that I can understand which narrows the field quite a bit).
This article, however, has some uncomplimentary things to say about Wuala's encryption technology.