In order to opt out of social advertising, the LinkedIn user has to take four steps to escape third-party advertisements:
Hover over the user name in the top right hand corner of any LinkedIn page and click ‘Settings’. On the Settings page, click ‘Account’. On the Account tab, click ‘Manage Social Advertising’. Uncheck the box next to “LinkedIn may use my name, photo in social advertising.” and click the save button.
via news.yahoo.com