The Yahoo Tech News of July 8 gives some details on a new hacking system with the headline "No One is Safe: $300 Gadget Steals Encryption Keys Out of the Air, and It's Nearly Unstoppable."
Here's the latest on Dropbox from Jim Hamm. "If you use Dropbox, as I do, you might have been concerned a few days ago when they updated their Terms of Service -- I certainly was. It appeared that by using Dropbox they owned everything we put in there. Not good. They are now backpedaling quite a bit, and this article gives an explanation of the subsequent revisions to Dropbox's T of S. Take a read and see if you feel more comfortable using Dropbox." (Earlier postings about Dropbox are here, dated 6-2-11 and 7-3-11.)
After questioning him about encryption Jim expounds further this morning (7-9), "Yes, there’s a Mac version for TrueCrypt available. If I were going to store sensitive data in Dropbox I might try TrueCrypt. Reading through the instructions it’s a bit of work to use TrueCrypt, though. Not something I want or plan to do with the data I use Dropbox for. I don’t like the idea of using any ‘Cloud’ service to store sensitive data, say, like a password to Amazon or a bank account. I keep that stored on my own Mac."