UK intelligence agencies are concerned that Facebook and other social networking tools are ruining the spy industry, says IT security consultancy, NCC Group.
National security advisors are finding it increasingly difficult to recruit people who do not have an online trail, according to Rob Cotton, chief executive of NCC Group.
Anyone with a Facebook account automatically has images in the public domain and is associated with a variety of organisations and other people, making it difficult to keep a low profile, he said.
"Having a Facebook profile, you are opening up a Pandora's box of online traceability that you can't ever truly close, which extends to close associates too," said Cotton.
The Mail on Sunday this weekend revealed that personal details about the UK's ambassador to the UN and future head of MI6, Sir John Sawers had been accessible to 200 million Facebook users.
The details were removed after the paper alerted the Foreign Office that Lady Sawers had posted the information on Facebook without any privacy restrictions.
The information is said to have included the location of the couple's London flat, the whereabouts of their three grown-up children and details of friendships with senior diplomats.
"There are security implications for anyone who puts personal details online, and we have long advised people to err on the side of caution should they chose to have a Facebook profile or similar," said Cotton.
The problem for national security staff is that once these details are out there, it is very difficult to erase them, and the wrong details in the wrong hands could actually lead to a life or death situation, he warned.
"For those in high-risk roles where information is like currency, something as innocuous as updating your profile could jeopardise a mission," he said.
Foreign secretary David Miliband has dismissed concerns that state security was compromised by the information made available by Lady Sawers on Facebook.
He said no state secrets have been revealed, but some politicians have called for government to provide assurances by investigating the security implications of the incident.