There was a recent NC State study on apps sharing permissions with ad libraries and possible security risks for user devices. The story looks to have been picked up across a number of publications, which may pique regulatory interest. Here's a link to an article on the study:
http://mashable.com/2012/03/20/android-ads-attack-study/
http://mashable.com/2012/03/20/android-ads-attack-study/