Anonymish social network Whisper is tracking some users' location even after they opt out of tracking, according to a new report. The Guardian says that in the course of discussing a partnership with the Los Angeles company, it discovered that Whisper monitors users' rough location regardless of whether tracking has been disabled, and re-wrote its terms of service this week to give itself explicit permission to do so.

The Guardian reports that Whisper built a tracking tool enabling it to pinpoint users' location to within 500 meters, an ability it has used to monitor messages sent from the Pentagon and the National Security Agency, among other targets. "A team headed by Whisper's editor-in-chief, Neetzan Zimmerman, is closely monitoring users it believes are potentially newsworthy, delving into the history of their activity on the app and tracking their movements through the mapping tool," the report says. "Among the many users currently being targeted are military personnel and individuals claiming to work at Yahoo, Disney and on Capitol Hill."

Whisper has entered into partnerships with news organizations, most notably Buzzfeed, to surface newsworthy posts. Most famously, the company found and promoted an accusation that Gwyneth Paltrow was having an affair; Paltrow and her then-husband, Coldplay singer Chris Martin, later divorced. The Guardian says Whisper is currently tracking a "sex-obsessed lobbyist" in Washington, DC, to learn which parts of the capital he is visiting. "He's a guy that we'll track for the rest of his life and he'll have no idea we'll be watching him," the newspaper quotes an unnamed Whisper executive as saying.

Zimmerman denied the accusations in the story in a series of tweets.

Zimmerman told another user the story is "100% false." Later, the company issued a full response to the Guardian's claims categorically denying that the company tracks users without their consent and saying that users must opt in to have their location tracked. Zimmerman said the quote about tracking a lobbyist "for the rest of his life" is "100% fabricated" and continued to answer questions from users on Twitter.

The argument has only continued from there, with the Guardian publishing a lengthy followup story that breaks down the situation and notes its confidence in the reporting. Zimmerman has continued to deny it, tweeting that the story "adds absolutely nothing new and continues to get many facts wrong."

Update October 17th, 10:30AM ET: This story has been updated to mention the Guardian's followup story and Zimmerman's reply. This story was previously updated on October 16th with a link to Whisper's full response.