Employers are increasingly blocking access to Facebook because they’re
concerned about the time wasted and the information leaked when workers
use social networks on company time.

About half of all companies block employee access to Facebook,
putting policies and access controls in place to keep workers working
and not connecting with their Facebook friends, according to security company Sophos.
In a poll of 600 workers, 43% said their company was blocking access to
Facebook, while an another 7% reported that usage of the Web site was
restricted and only those with a specific business requirement were
allowed to access it.

Full Story at informationweek.com