I was reminded again last night when I discovered, and installed, the cool GDocs app on the Droid, that we seem to routinely give away account ID's and Passwords to allow apps to access the data they need to work.
Not sure about the rest of you here, but I have a boatload of docs/spreadsheets in Google Docs, not to mention 10 years of Yahoo email I just moved over to Gmail in anticipation of getting the Droid. All that content is there in the Google cloud, and full accessible by who-knows-who that's behind the apps we happily download off the Market.
Now I don't have highly private info in any emails or Gdocs (like bank account info, for instance) and never have, but still, there is so much data that, when aggregated, might reveal a surprisingly accurate profile.
Keep in mind that common practices by companies like FaceBook for instance are to take a snapshot of everything they can when you first provide access to your personal info, so even changing your password after the fact does not delete what they've already taken, and stored for their own use in the future.
So how do you folks manage the privacy issue in this highly connected/integrated world??