IAB develops new guidelines for behavioural advertising

Self-regulatory and signed by AOL, Google, Microsoft, Yahoo!... The guidelines can be summarized as:

• Notice

Each Member shall provide clear and unambiguous notice to users that it collects data for the purposes of OBA. This notice shall include information about what types of data are collected, how these data are being used and how users can decline OBA with respect to that Member.

• User choice
  

Each Member shall provide an approved means for consumers to decline OBA from that Member and information on how to do it.

• User Education

Each Member shall make information available to educate users about OBA and ensure that this information is easily accessible.

And of course, "No Member shall create OBA segments intended for the sole purpose of targeting children under the age of 13 years".

Full guidelines on IAB site.
First read on the BBC.