The men ran a bogus agency that tried to dupe them by demanding money to register under the Data Protection Act.
Leeds Crown Court sentenced three men to prison on June 8 for running the fake data protection agency, and the ICO fears it is just one of many illegal data operations throughout the UK.
Simon Entwisle, chief operating officer at the Information Commissioner's Office, said: "If a business receives a letter out of the blue demanding more than £35 to register under the DPA then this will be a scam. Our simple message to businesses is to disregard the letter and do not pay the fee demanded."
The fraudsters sent thousands of letters to businesses demanding £135 to register under the DPA, which could have netted them a potential £2m. They banked £62,575 before police uncovered the scam, with thousands of printed bogus forms ready to be posted.
Liaquat Khan, aged 33 of Leeds, admitted two charges of conspiracy to defraud and was jailed for two and a half years. Parminder Kaur Johal, aged 31, and Zahir Abbas Shah, aged 33, both from Bradford, also admitted two charges of conspiracy to defraud and were jailed for 13 months and 8 months respectively.
A fourth person, Nosheen Sheridan, aged 27 from Bradford, admitted one charge of conspiracy and was given an 18 month supervision order with 50 hours unpaid work.
Detective Sergeant Lester Lee from West Yorkshire Police said: "The sentences passed today show that the courts take this kind of crime seriously. Anyone thinking of getting involved in such an offence should take note that we painstakingly investigate these crimes until we are able to put the offenders before the courts".
West Yorkshire Police, West Yorkshire Trading Standards, the Health and Safety Executive and staff at the Information Commissioner's Office worked together to ensure the convictions.