"Blocking encourages employees to bypass corporate systems and blinds an organization to what they are doing in public social media," he told the Gartner Security & Risk Management Summit 2011 in London.
Experience has shown that organizations that block access to social media are at a higher risk of non-compliant behavior, Walls said.
A growing number of businesses are beginning to understand this, with the number that block access to social media falling by roughly 10% a year, he said.
Walls estimates that by 2014, less than 30% of large enterprises will block social media.
By embracing social media, he said, businesses can have far greater visibility of what employees are doing if they deploy controls at the endpoint, on the network and the social media platform.
"It is important that businesses invest in monitoring tools to get the visibility they need to make risk assessments for social media to augment their existing risk assessment process," he said.
Education is also another important investment when it comes to social media. "Make users aware of the dangers. The more you can influence behavior, the more control you will have," said Walls.
This story was first published by Computer Weekly