Just reading this article at CSO on the dangers of using mobile devices and it specifically mentions the John McCain incident:
...officials with John McCain's campaign mistakenly sold a Blackberry to a Fox television reporter for US$20 in a fire sale...
News like this makes me glad that the most of our clients that use either Blackberries or Windows Mobile devices are using Handheld Contact (aka HHC) to sync their data to their handheld.
I AM GLAD because Handheld Contact has an option on the server side to "Erase data from handheld" which will erase all data sent to the handheld by HHC which is all the contact info for all the contacts.
If a client loses their Blackberry, all it takes is a phone call to their system admin (or me), a couple of mouse clicks and a large chunk of sensitive information is removed from the Blackberry.