The number of victims of identity fraud rose by 57% last year, according to new figures.
Experts at Cifas, a service that gathers information from hundreds of financial firms, fear that a lack of awareness about the crime is making it easier for conmen, who use social media as their "hunting ground", to steal cash.
It found that there were 148,463 victims of the crime in 2015, compared with 94,492 the previous year.
The largest rises were seen among the 31-40 and 51-60 age groups, with rises of 64% and 60% respectively.
Cifas also highlighted that the number of victims aged 30 and under more than doubled between 2010, when 11,000 fell prey, and 2015, when 23,959 were targeted by fraudsters.
The criminals glean personal information from social media and hack into private systems to get details such as a person's name, date of birth, address and name of their bank, and then can apply for a loan or buy a product in their name, leaving the innocent party to foot the bill.
Cifas chief executive Simon Dukes said: "Fraudsters are opportunists. As banks and lenders have become more adept at detecting false identities, fraudsters have focused on stealing and using genuine people's details instead. Society, government and industry all have a role in preventing fraud, however our concern is that the lack of awareness about identity fraud is making it even easier for fraudsters to obtain the information they need.
"The likes of Facebook, Twitter, LinkedIn and other online platforms are much more than just social media sites - they are now a hunting ground for identity thieves. We are urging people to check their privacy settings today and think twice about what they share. To a fraudster, the information we put online is a goldmine."
The largest rises in identity fraud against those aged 21-30 in major UK cities were seen in Manchester, where there was an 83% jump, and London, where there was a 78% increase.
In 2015, 86% of the identity fraud cases recorded by Cifas members were committed online. Only 3.4% of cases involved fictitious identities rather than real ones.