According to IT and technology company Morse, 57% of employees use Twitter or some other form of social networking during the working day for personal use. And on average these users spend 40 minutes each week using these sites.
The research also revealed on average office workers think their colleagues spend nearly an hour (59 minutes) each day at work on social networking sites.
Philip Wicks, a consultant at Morse, said: "The popularity of social networking sites such as Twitter and Facebook has grown considerably over the past couple of years. However, with it has come the temptation to visit such sites during office hours. When it comes to an office environment the use of these sites is clearly becoming a productivity black hole.
"The recent case of Portsmouth City Council banning Facebook access for all employees was a high-profile example, but it is clear that businesses shouldn't turn a blind eye to their employees' use of social networks, and instead look to formulate and enforce sensible usage policies."
Despite a third of office workers admitting that they had seen sensitive information posted on social networks, 84% felt that it should be up to them as to what they post online. This indicates that guidelines are either being poorly communicated or are not strict enough.
Particularly when it comes to Twitter, many businesses also face security threats due to the increased use of URL shortening, meaning that employees can't see the original address for the website they may be visiting. This potentially leaves employees open to phishing scams, malware and computer viruses, which could compromise a business's IT security.
Of the office workers surveyed, 81% admitted that they were worried they might be clicking on a link to an unsecure website.
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