Facebook users are being warned against showing their full name and email address on their profiles this Christmas because it leaves them open to identity fraud.
Credit reporting service Noddle has found that one in six Facebook users in the UK displays both pieces of information which it says is enough for cyber criminals to carry out identity theft.
The company claims that this equates to four million people in the UK who are potentially at risk.
With millions of people opening new internet-connected devices this Christmas, many will post images of their new presents online. Noddle says this could leave them and their data vulnerable.
John Cannon, the firm's fraud and ID director, said: "Social media has become as much a part of Christmas as tinsel, turkey and all the trimmings.
"Yet, by sharing important data like your full name, email address or date of birth - alongside your pictures of presents, decorations or the tree - you can inadvertently be putting yourself at risk.
"If a fraudster has picked up compromised data, from something like a data breach, then a quick scan of your public social media profile can be all they need to confirm who you are to commit fraud or to launch a convincing phishing attack.
"Criminals can do this in the time it takes you to eat the first course of your Christmas dinner."
Cannon warned against a number of phone fraud scams that use the information taken from Facebook profiles.
Criminals could pose as a charity that a Facebook user has 'liked' for example and ask to set up a direct debit to get your bank details.
In order to reduce the risk of cyber fraud, Noddle has called on users to check and reinforce their privacy settings on social media, as well as reconsider the amount of personal information they have on a public profile.
Meanwhile, Facebook has announced that it has stopped using Adobe Flash technology to show videos and is instead moving its support to HTML5 technology.
Adobe's Flash has been gradually phased out by many websites as a means of playing videos because many see it as a security issue.