Contractual obligation? What contract? I guarantee you that the clickthrough agreement the blogger signed explicitly said that Google might do what it's doing now.
Moral obligation? If you start saying that someone providing a service has a moral obligation to open themselves to civil suits on behalf of the people they serve then you'd see a lot fewer people offering free services.
Moral obligation? If you start saying that someone providing a service has a moral obligation to open themselves to civil suits on behalf of the people they serve then you'd see a lot fewer people offering free services.