'Zombie' Cookies Potential Headache for Verizon, Turn

Telecoms giant Verizon and ad targeting company Turn are the subject of a potential class action privacy lawsuit over their use of ad tracking tools including 'zombie' cookies.

According to www.mediapost.com, Emma Michael of Jackson, Mississippi filed the suit last week claiming that Verizon violates a number of privacy and fraud laws when it tracks customers' online activity by inserting headers called UIDHs into mobile traffic. UIDHs are sometimes known as 'zombie' cookies because they can be restored to life after deletion by the user.

The complaint says users consider their online activities confidential and reasonably rely on browser settings to control cookies. Verizon has always allowed opt-out from its own targeted ads but until now, not from the UIDH insertions, which can be used by third parties to target the users. Recent research has shown this has in fact been done, by Turn, a behavioral advertising company which has partnered in the past with the likes of Experian and eXelate, and has been rapidly developed its products in the last year after securing $80m in a Series E round of financing.

Since publication of the research - by Stanford's Jonathan Mayer - Turn has said it will stop using the zombie cookies, but Verizon is now under pressure from campaigners to cease their use altogether.