The chance to win theatre tickets is enough to make people give away their identity, reveals a survey.
Many of those questioned revealed pet names too
Of those taking part 92% revealed details such as mother's maiden name, first school and birth date.
The detailed personal information was gathered by market researchers who asked the questions as part of a fake survey on theatre-going habits.
Dangling the chance to win free tickets was enough to make people surrender everything needed to impersonate them.
During the course of the survey many people freely volunteered key details such as name, address and postcode.
To elicit other details the questions asked by the market researchers were cleverly put together to make people hand over personal information.
One of the questions was about the way that actors pick stage names. Those taking part in the survey were told that many stage names are created using a pet's name and the actor's mother's maiden name.
When asked what their stage name would be using the same criteria, 94% volunteered information.
Such data is potentially hugely valuable to identity thieves who need it to answer the supplementary security questions many websites impose on those signing up.
By the end of the survey, the fake researchers had everything they needed to pose as those taking part, to take out credit cards in their name and even open bank accounts.
Chris Simpson, head of Scotland Yard's computer crime unit, said the results of the survey were "disturbing" and added: "Preventing the theft of your own identity is relatively simple, but it relies on the individual taking steps to protect themselves."
Mr Simpson said people should share sensitive data with as few people as possible, shred personal correspondence before throwing it away and never share passwords across different computer systems.
The Home Office reports that more than 100,000 British people every year suffer identity fraud.
The survey, which questioned 200 people stopped on London streets, was carried out for Infosecurity Europe which takes place from 26-28 April.