Here's some fun legalese..
You know, in relation to credit card data clauses 11.1 and 11.2 of the Google Terms of Service appear to be very entertaining. IANAL, but this reads as Google being able to change your transaction at will, and use your credit card data to sell you whatever crap they feel like :).. Puts a whole new spin on the "I feel lucky" button, doesn't it?
Extract from google.com/accounts/tos :
11.1 [..] By submitting, posting or displaying the content you give Google a perpetual, irrevocable, worldwide, royalty-free, and non-exclusive license to reproduce, adapt, modify, translate, publish, publicly perform, publicly display and distribute any Content which you submit, post or display on or through, the Services. This license is for the sole purpose of enabling Google to display, distribute and promote the Services and may be revoked for certain Services as defined in the Additional Terms of those Services.
11.2 You agree that this license includes a right for Google to make such Content available to other companies, organizations or individuals with whom Google has relationships for the provision of syndicated services, and to use such Content in connection with the provision of those services.