This week’s headlines: Tumblr Launches Sponsored Trending Blog Ads, Facebook Updates Newsfeed Algorithm to Benefit Publishers, Apple Acquires Topsy, Twitter Launching Retargeted Ads and Foursquare Adds Smart Recommendation Notifications.

The week’s news quick hits: Facebook Launches Unfollow Button, New Jersey Makes Employers Requesting Social Media Passwords Illegal, Datasift Receives Additional Funding, Twitter Relaunches Media Site with TV Section, Twitter Inks Deal with Deutsche Telekom, Google Adds Export Feature for Gmail and Google Calendar and Instagram to Hold Event on December 12.