According to the BBC News website over the weekend:

US troops are to be allowed to use social networking websites such as Twitter and Facebook following a review of internet use and security.

Defence department officials say the benefits of using social media now outweigh the risks to security.

The ruling means that a number of sites blocked by the Pentagon in 2007 - including YouTube - will be unblocked.

However, commanders will be able to temporarily block access to safeguard missions or save bandwidth.

Correspondents say social media and the internet are becoming increasingly important for the US military.

The web is used for recruitment, public relations and for communications between troops and their families, among other things.

US Defence Secretary Robert Gates has said that social networking can help the Pentagon interact with US military employees, many of whom are in their early 20s and regular users of online services.

For more details see Twitter and Facebook access for US troops.