[i336_]

I was considering asking if anyone at Google could shed some more light on this - thanks for taking the initiative and making accounts both here and on Reddit just to reply!

You pretty much covered everything I could think of and more. :)

The only thing I thought of would be to filter all of Google Code for projects with private data, then mass-email a form letter to everyone relevant telling them their non-public data soon won't be available. I don't have anything up on Google Code so I have no idea if you're not already doing something like this.