If you don't want someone else reading your files, don't send them your files. I'm not really understanding all the uproar over Dropbox. I guess it's a side effect of becoming the established leader. They host my photos, some code I don't particularly care about and some other random junk like my resume. I guess if they want to read up on my employment history they are welcome too, but I'm surprised at how many people here seem to be uploading sensitive data to a third party and then getting grumpy about the idea (not even the accusation) of that third party being able to access it.
The thing about Dropbox is that they were making the same claims (from the perspective of a non-technical person) that other you-manage-your-own-encryption-key cloud storage sites were making. You put someone non-technical in-front of the marketing materials of say, Jungledisk, and Dropbox and people might even come away thinking that Dropbox must be even more secure since they're the market leader. And that's part of the problem in this case -- leadership implies trust.
Dropbox used to have a FAQ somewhere that made of point of informing users that they cannot set their own encryption key (but Dropbox hoped to implement that functionality soon). Anyone with technical chops can read that and know that the encryption key(s) are centrally managed on the Dropbox internal network and anyone gaining access to that internal network can gain access to all of the documents. But your average non-techie accountant, CEO, or sale guy...?
