[notatoad]

It's definitely an interesting case. It seems clear that scanning email solely for the purpose of providing advertisements against it would be illegal (let's ignore the discussion of whether or not this is a stupid law). It also seems clear that scanning emails for spam and categorization is legal. So given that google has a legal reason for scanning the content of emails, is there anything prohibiting them from using the data from that scan for their other business activities? It sounds to me that once you have the reason to get the data, how you actually use it is just up to the product's TOS.

and regarding your last paragraph, you have to remember that this is all consented to by the user. it's not akin to somebody reading and selling your mail before they deliver it to you, it's akin to somebody doing that because you hired them to.

[reddiric]

There's lots of liability you can't skirt by saying it's implied that the other person consented. It seems like saying someone consented to waving the accessibility rights afforded under the ADA because it was a condition of patronizing the store.

And I don't follow why you think once you have a reason to use data for one purpose, you automatically have the right to use it for any purpose.