• by Wendy Davis  @wendyndavis, June 23, 2015

Ad company Turn has been hit with a second lawsuit stemming from its use of a controversial “supercookie” tracking technology, which enabled the company to send targeted ads to consumers -- even when they deleted their cookies.

“Turn has compiled deeply personal and private information without users' knowledge or consent by tracking website usage,” California resident Deena Kay alleges in a complaint filed last week in Los Angeles County Superior Court. “Turn's supercookie is designed to evade detection and deletion by the normal process of deleting cookies or using a private browser.”

She alleges in a potential class-action lawsuit that Turn's use of the technology violates California's Unfair Competition Act and other state laws, including one regarding invasion of privacy.

The allegations stem from reports that Turn tracked Verizon users' Web activity by drawing on headers that the telecom injects into mobile traffic. The headers, called UIDHs, enable ad companies to compile profiles of users and serve them targeted ads. The UIDHs also are called “supercookies” and “zombie” cookies, because the headers enable ad companies to recreate cookies that users delete.

“Turn unfairly invaded the privacy of Verizon subscribers by tracking and storing their personal browser history without their consent or knowledge [and] sold that information to third parties for financial gain,” the lawsuit alleges.

Kay is seeking to represent a class of all Verizon subscribers who reside in California. She is represented by Brian Kabateck, who previously obtained “click fraud” settlements from Google and Yahoo in separate cases.

Last year, privacy advocates raised concerns that outside ad companies could draw on the UIDHs to target Verizon users. At the time, Verizon dismissed that scenario as unlikely.

But in January, Stanford's Jonathan Mayer published research showing how Turn leveraged the headers for its behavioral advertising program. Several days later, Turn said it would stop doing so. The company declined to comment for this article.

When Verizon first began using the headers, the company allowed people to opt out of receiving targeted ads powered by its own ad programs, but didn't let users avoid header insertions. But in April, the company began allowing subscribers to opt out of the headers.

Earlier this year, two New York residents sued Turn in federal court over its alleged use of supercookies. Turn has asked U.S. District Court Judge White in the Northern District of California to send that matter to arbitration, arguing that Verizon's contract with users requires arbitration of all disputes.

The consumers who are suing oppose that request. They argue that their subscriber agreements with Verizon aren't relevant to the lawsuit against Turn.