Half of employees are blocked from accessing Facebook at work, according to research by IT security and control firm Sophos.

Itfound that employers are worried about the website’s impact on productivity and security.

The study also revealed that 66% of workers were concerned that their colleagues were sharing too much information on Facebook.

Graham Cluley, senior technology consultant at Sophos, says: “Companies are split on the question of Facebook. Some believe it to be a procrastinator’s paradise which can lead to identity theft if users are careless. Others view it as a valuable networking tool for workers or are too nervous of a backlash from employees if the site is suddenly blocked.”