UPDATE: The makers of the controversial Sell Hack browser plug-in responded this afternoon to a cease-and-desist order from LinkedIn and confirmed their extension no longer works on LinkedIn pages and that all of the publicly visible data it had processed from LinkedIn profiles has been deleted.
“We’ve been described as sneaky, nefarious, no good, not ‘legitimate’ amongst other references by some,” the Sell Hack team said. “We’re not. We’re dads from the Midwest who like to build web and mobile products that people use.”
LinkedIn said none of its member data was put at risk by the two-month-old Sell Hack’s plug-in.
According to the Sell Hack website, once the browser extension is installed and a user browses to a social media profile page, a “Hack In” button is visible that will search the web for email addresses that could be associated with a particular profile.
According to another post on the Sell Hack blog: “The magic happens when you click the ‘Hack In’ button. You’ll notice the page slides down and our system starts checking publicly available data sources to return a confirmation of the person’s email address, or our best guesses.”
LinkedIn’s legal team reached out to Sell Hack with its cease-and-desist last night.
“We are doing everything we can to shut Sell Hack down,” said a LinkedIn spokesperson. “Yesterday LinkedIn’s legal team delivered Sell Hack a cease and desist letter as a result of several violations. LinkedIn members who downloaded Sell Hack should uninstall it immediately and contact Sell Hack requesting that their data be deleted.”
While the issue may not be a security vulnerability, since the Snowden leaks began, technology providers are ultra-sensitive about maintaining the privacy of their users’ data, which in this case is being collected and sold without consent.
“We advise LinkedIn members to protect themselves and to use caution before downloading any third-party extension or app,” LinkedIn said. “Often times, as with the Sell Hack case, extensions can upload your private LinkedIn information without your explicit consent.”
LinkedIn is one of a handful of major technology providers who lobbied hard against the government for additional transparency in reporting government requests for user data. Many of those same companies were initially accused of providing the government direct access to servers in order to obtain user data.
Unlike other providers such as Google or Facebook, LinkedIn does not offer Web-based email or storage. Instead, its appeal to the intelligence community was its mapping of connections between its hundreds of millions of members.
LinkedIn called the transparency ban unconstitutional in September; the technology companies eventually won out in January when the Justice Department agreed to ease a gag order that prevented the companies from reporting on national-security-related data requests.
This article was updated on April 1 with additional comments from LinkedIn and the Sell Hack team.