Last week, while looking at Google Voice I noticed a button that said “Get $10″. I thought it meant “get $10 credit for trying it” so I pushed the button. Ten dollars credit showed up. Since Google Voice is free for the calls I make I had no use for $10 credit but maybe someday…. A few days later I happened to look at my credit card bill. Google had billed me $10! I didn’t even know they knew my credit card number! It hadn’t been required for the $10 transaction. I haven’t consciously used Google Checkout. I haven’t given it to them in any other connection. Talk about data mining… When I go to Account Settings listed under my Gmail address, one of the sections is My Products, meaning My Google Products. Under that is listed Google Checkout, although I’ve never signed up for it and (I thought) never used it. So why is it there? I looked in Google Checkout. The Google Voice $10 transaction is the only transaction listed. As far as I can tell, this proves I didn’t use Google Checkout in the past (say, 4 months ago) and forget about it. Google really did get and use my credit card number without telling me, much less asking me. My credit card company quickly gave me a refund.