Based on an international research project on the uses of digital technologies by job seekers and recruiters, this chapter questions how social media intervene in the matching of demand and supply in various sectors of the job market. Results indicate that social network sites represent a key interface for all parties involved, as job seekers actively engage in social media activity to find job opportunities, and recruiters similarly declare using social media for purposes of screening. The chapter argues this amounts to a form of pre-emptive control on the side of recruiters that enables them to access an unprecedented set of information about prospective candidates and use social media as spaces of observation and surveillance.