Verizon phones can apparently track you, even if you try to stop them. This month a Stanford University lawyer confirmed on his blog what cybersecurity experts have warned for a while: You can delete cookies on Verizon phones, but the company's so-called "supercookies" remain, allowing advertisers to target you anyway, the New York Times reports. "Verizon is not in a position to control how others use its [tags]," says the lawyer, Jonathan Mayer. "There’s no doubt that this particular approach does introduce new privacy problems." Others have noticed, too: After ProPublica reported on the practice this month, the ad software company Turn agreed to stop tracking Verizon users for ad sales.
"We feel this practice is legal," says a Turn executive, but privacy concerns have persuaded them to stop "as soon as we get the new codes rolled out." Turn, a Verizon customer, uses the phones' tags to track online habits and sell ad space to companies targeting people based on their interests. And Verizon's not alone: AT&T tried a similar system last year but shelved it under news-media scrutiny. And companies like Yahoo and Facebook allow advertisers to target users in similar ways. While activists seek to reclassify telecom companies as "common carriers"—which would limit their legal right to share data—Verizon says it's reconsidering the "supercookie" practice. "They did not talk to me," says Verizon's technology director of the new revelations. "If they did, I would not have been satisfied."