On questions like these, I always refer to the Terms and Conditions and the Program Policies.
Here's what the Terms and Conditions say:
Confidentiality. You agree not to disclose Google Confidential Information without Google's prior written consent. "Google Confidential Information" includes without limitation: (a) all Google software, technology, programming, specifications, materials, guidelines and documentation relating to the Program; (b) click-through rates or other statistics relating to Property performance in the Program provided to You by Google; and (c) any other information designated in writing by Google as "Confidential" or an equivalent designation. However, You may accurately disclose the amount of Google’s gross payments to You pursuant to the Program. Google Confidential Information does not include information that has become publicly known through no breach by You or Google, or information that has been (i) independently developed without access to Google Confidential Information, as evidenced in writing; (ii) rightfully received by You from a third party; or (iii) required to be disclosed by law or by a governmental authority.