But the information they’ve already got, even if they were to get no more data starting tomorrow, is Gargantuan. Your point on the credit-card industry: lots of info, and a lot of defacto power too… Experian could pretty much ruin your commercial life if they wanted to. A bad credit rating can thwart a lot of freedom.
“But if there’s ever concern of Google going bankrupt or something like that – that’s when we need to start worrying.” Great point: think of JPM’s control of WaMu… an out of state bank owns a vast quantity of debt and property in WA.
If Google ever went bankrupt as you conjectured (never say never), there’s no telling who could end up reading our gmail. Maybe even a government: foreign or not, YIKES.

BTW, sorry about the comment approval issue, was an oversight, should be able to comment anytime without a wait.

And that’s the small stuff – the more worrisome stuff is what you’re talking about – massive amounts of personal information. But then again, credit card companies have tons of personal information on us too. As long as they’re making hundreds of millions or billions of dollars, don’t worry. But if there’s ever concern of Google going bankrupt or something like that – that’s when we need to start worrying.