A WebmasterWorld thread reports a change to the Yahoo Search Marketing terms of service. The change basically says that Yahoo can add or edit your ads and you must pay for the clicks on those ads. Here it the legalize:
OPTIMIZATION. In the U.S. only, for those advertisers not bound by an Insertion Order, we may help you optimize your account(s). 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. If you would like any of such changes reversed, please reply to such email within 14 days of the change(s), and we will make commercially reasonable efforts to reverse the change(s) you specifically identify. Notwithstanding the foregoing, you remain responsible for all changes made to your account(s), including all click charges incurred prior to any reversions being made. It is your responsibility to monitor your account(s) and to ensure that your account settings are consistent with your business objectives.
Read that carefully.
Yahoo "may help you optimize your account(s)." You "expressly agree that we [Yahoo] may also: (i) create ads, (ii) add and/or remove keywords, and/or (iii) optimize your account(s)." Not only that, "you remain responsible for all changes made to your account(s), including all click charges incurred prior to any reversions being made." Yes, you are responsible for the changes Yahoo makes.
Crazy stuff and the forums are buzzing about it right now.
Forum discussion at WebmasterWorld and Search Engine Watch Forums and Sphinn.