A new tool called Sell Hack claims it allows anyone to see the email address of a LinkedIn user. We contacted LinkedIn about it this morning and the company responded in the evening to say the company’s legal team is delivering a cease and desist letter to Sell Hack “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.” Krista Canfield, LinkedIn’s Senior Manager of Corporate Communications, told TNW in a statement. “We advise LinkedIn members to protect themselves and to use caution before downloading any third-party extension or app. Often times, as with the Sell Hack case, extensions can upload your private LinkedIn information without your explicit consent.”