For the last several months, cybersecurity experts have been warning Verizon Wireless that it was putting the privacy of its customers at risk. The computer codes the company uses to tag and follow its mobile subscribers around the web, they said, could make those consumers vulnerable to covert tracking and profiling.

It looks as if there was reason to worry.

This month Jonathan Mayer, a lawyer and computer science graduate student at Stanford University, reported on his blog that Turn, an advertising software company, was using Verizon’s unique customer codes to regenerate its own tracking tags after consumers had chosen to delete what is called a cookie — a little bit of code that can stick with your web browser after you have visited a site. In effect, Turn found a way to keep tracking visitors even after they tried to delete their digital footprints…

While Internet users can choose to delete their regular cookies, Verizon Wireless users cannot delete the company’s so-called supercookies…

Indeed, after a report on the practice by ProPublica, Turn announced it would suspend its use of Verizon’s ID codes to regenerate tracking cookies and reconsider its use of the technique…

Verizon is now at the forefront of telecommunications companies selling intelligence about their customers to advertisers…

The ad-targeting experiments by Verizon and AT&T are striking examples of the data-mining opportunities open to phone carriers now that they have become the nexus of the information universe, providing a connection to the Internet for people anywhere they go, at any time…

Some leading data-privacy and security experts contend that Verizon’s use of unique and persistent customer ID tags makes its subscribers vulnerable to covert online tracking by third parties.

Harold Feld, a senior vice president at Public Knowledge, a nonprofit group that focuses on information policy, said..“Stuff like this is worse than what Google or Facebook or anyone else does,” Mr. Feld said.

“I can avoid Google and Facebook, in theory at least. But if the network operator is going to spy on me, there is nothing I can do about it.”

Cripes. One more category of snoop we get to feed with information for free – so they can profit.