No doubt this is 90%+ a PR move, it also provides some real benefits:
* Customers bound by HIPAA or other data privacy regulations may require encryption at rest, so this opens up a new market.
* Assuming Google didn't warranty-return failed disks with cleartext on them, Disks may be returned under warranty instead of held/destroyed which may partially or completely offset the additional cost of the encryption.
This definitely would not provide any additional barrier to a legitimate subpoena or the NSA/secret police -- only the customer controlling their own keys and encrypting the data before transit to Google could do that. Even then, there is no way to know if the NSA has a backdoor baked into the encryption anyway... Big brother is watching, and this will have zero impact on that.
* Customers bound by HIPAA or other data privacy regulations may require encryption at rest, so this opens up a new market.
* Assuming Google didn't warranty-return failed disks with cleartext on them, Disks may be returned under warranty instead of held/destroyed which may partially or completely offset the additional cost of the encryption.
This definitely would not provide any additional barrier to a legitimate subpoena or the NSA/secret police -- only the customer controlling their own keys and encrypting the data before transit to Google could do that. Even then, there is no way to know if the NSA has a backdoor baked into the encryption anyway... Big brother is watching, and this will have zero impact on that.