...the advertisers permission on this matter. Barry Schwartz, has given a brief information on the issue.

Have a look at the the current version and the archived version of the terms and conditions. Here is the snippet of the terms and conditions that states:

Accordingly, you expressly agree that we may also: (i) create ads, (ii) add and/or remove keywords, and/or (iii) optimize your account(s). We will notify you via email of such changes made to your account(s), and can also include a spreadsheet of such changes upon your written request.

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