Andy Smith, an internet security chief at the Cabinet Office, has urged users to give websites fake details to protect their identity.Labour has spoken out against the comments, claiming that they encourage cyber crime and bullying.
Smith told a Parliament and the Internet Conference in Westminster that real names and addresses posted on social networking sites "can be used against you" and that internet users should only provide their details to trusted websites, such as those created by the government.
He said: "When you put information on the internet do not use your real name, your real date of birth.
"When you are putting information on social networking sites don't put real combinations of information."
Smith argued that online fraudsters collect a lot of their information from social networking sites and Google.
Helen Goodman, Labour MP for Bishop Auckland and shadow culture minister, told the BBC that Smith's advice was "totally outrageous".
"This is the kind of behaviour that, in the end, promotes crime. It is exactly what we don't want. We want more security online. It's anonymity which facilitates cyber-bullying, the abuse of children," she said.
"I was genuinely shocked that a public official could say such a thing."
Culture minister Ed Vaizey has also backed Goodman and said that he wouldn't encourage people to put false identities on the internet.
Vaizey told the BBC: "The way of viewing this issue is that we should with Facebook to ensure people feel secure using those sites and that there is not a threat of identity theft."