Hidden tracking code has been discovered by users of the anonymising web browser Tor who visited a child sex abuse image site . The script sent information about their vulnerability to a server in France and there are concerns it may have been used on other sites to track law - abiding users . mark Veditz , security lead at Firefox - maker Mozilla , said it bore the hallmarks of the " network investigative technique " used by the FBI to deanonymise Tor users . An update to the web browser has disabled the browser and the website in question was deleted on 15 November .
Hidden tracking code has been discovered by users of the anonymising web browser Tor who visited a child sex abuse image site. The script sent information about their computers to a server in France and there are concerns it may have been used on other sites to track law-abiding users. Daniel Veditz, security lead at Firefox-maker Mozilla, said it bore the hallmarks of the "network investigative technique" used by the FBI to deanonymise Tor users. An update to the Tor browser has disabled the tracker and the website in question was removed on 15 November.