The Google Ads policy on "trick to click" in image ads will change around August 20. The policy is changing to prohibit all black, white, or transparent background ads without borders. The change will affect all countries. We made this decision for the benefit of the user and publisher experience, as well as enforcement consistency. We'll send notifications to affected advertisers.
After the new policy goes into effect, the policy description will be updated to reflect this change.
(Posted in August 2013)