Verizon Wireless will pay $1.35 million to settle an FCC probe into its practice of inserting so-called "super cookies" into its customers' mobile Internet traffic without their knowledge or consent.

At issue are tracking cookies intended to serve up relevant ads. Verizon inserts these identifiers, known as UIDH, into Web traffic to identify customers and ultimately deliver them targeted ads. Researchers, however, found that Verizon partners could track users even if they deleted their cookies.

As a result of the investigation and settlement, "Verizon Wireless is notifying consumers about its targeted advertising programs, will obtain customers' opt-in consent before sharing UIDH with third parties, and will obtain customers' opt-in or opt-out consent before sharing UIDH internally within the Verizon corporate family," the FCC says.

The FCC probe dates back to December 2014, when the agency launched an investigation into whether Verizon's practice violated the FCC's Open Internet Transparency Rule and the Communications Act. The investigation found that Verizon began inserting these identifiers into customers' Internet traffic as early as December 2012, but failed to inform customers about the practice until October 2014.

Last year, Verizon said it would let users opt out of being tracked by these super cookies. According to The Verge, the settlement means those who don't opt out will also get to "limit who gets to see their information." 

"Consumers care about privacy and should have a say in how their personal information is used, especially when it comes to who knows what they're doing online," FCC Enforcement Bureau Chief Travis LeBlanc said in a statement. "Privacy and innovation are not incompatible. This agreement shows that companies can offer meaningful transparency and consumer choice while at the same time continuing to innovate."

AT&T, meanwhile, phased out the use of super cookies in November 2014.

This article originally appeared on PCMag.com.