Regulators from the European Union are expected to make online advertising targeting a priority in the new year, reports Reuters.

Research over ad targeting will be conducted primarily by a working group within the body that is looking at issues relating to data protection.

The impetus for the review comes in part from Facebook users who feel the social network's new system for gathering information and showing it to friends — what Facebook calls conversational marketing — violates their privacy. 13,000 Facebook users have reportedly signed a petition protesting the new ad targeting system.

Publishers and advertisers say targeted advertising brings in a more certain ROI and more revenue, respectively. They say untargeted ads will only result in more advertising, since everyone will just throw more ads at users to substitute impressions for targeting.

The EU working group will also review privacy issues that drove Google to trim its user data retention time to 18 months.

Last week, Google admitted to illicitly using Facebook data to beef up AdWords campaigns associated with its open apps program.