Last week, an investigative report by journalists at the Hamburg-based German television broadcaster, Norddeutscher Rundfunk (NDR), revealed that Web of Trust Services (WoT) had been harvesting netizens' web browsing histories through its browser add-on and then selling them to third parties.
WoT claimed it anonymised the data that it sold but the journalists were able to identify more than 50 users from the sample data it acquired from an intermediary.
The journalists added that the browsing histories they obtained also identified information about ongoing police investigations, businesses' sensitive financial details and information which suggested the sexual orientation of a judge.
NDR quoted the data protection commissioner of Hamburg, Johannes Caspar, criticising WoT for not adequately establishing whether users consented to the tracking and selling of their browsing data.
Those consent issues have resulted in the browser add-on being pulled from the add-on repositories of both Mozilla Firefox and Google Chrome, although those who have already installed the extension in their browsers will need to manually uninstall it to stop their browsing being tracked.