Sometimes they posed as doctors to trick pathology companies in releasing personal information on patients.
Other times they bamboozled banks and power companies with the right questions to confirm birth dates and other sensitive details on clients.
Or they simply used cash to bribe a Department of Human Services employee to look up the valuable details herself.
Detectives believe a "highly sophisticated" criminal network allegedly used a range of successful tactics to fleece millions of dollars out of thousands of unsuspecting people by taking over their identities to either steal directly from their accounts or rack up credit card debt in their names.
Seven people were arrested in a series of raids across Sydney on Wednesday as the Identity Security Strike Team, a multi-jurisdictional initiative between NSW Police and Australian Federal Police, swooped following a five-month investigation. On Thursday, the four men and three women were charged.
The amount of paperwork and items allegedly seized during the seven raids was so large, police believe it could take more than six months to contact all of the alleged victims and potential victims.
Included in those arrested was Blacktown woman Kristiane Soqosoqo, a Department of Human Services customer services representative who is now set to face Commonwealth bribery charges.
Detective Superintendent Brett James, the Organised Crime and Cyber coordinator for the Australian Federal Police, said it was alleged she gained access to Australian Government databases to obtain personal information for the syndicate in exchange for cash.
"We believe this was an opportunistic criminal network essentially operating a basic mail theft and phishing scheme where they realised that they had a personal contact and they could leverage off the privileged access to information that person had," Detective Superintendent James said.
"Two aspects allowed this network to flourish. The access to government information is one but the ease of access to personal information through mail theft and through business and individuals giving away their identities and their personal information over the phone was another."
Detectives will allege the syndicate "put jigsaws together" by beginning with a piece of personal information and building on it through phone calls.
They would allegedly then steal money from the bank accounts of identities they had stolen, or rack up debt on credit cards in their name.
"In many instances they were aware of the procedures from some of these financial companies and institutions. They knew the questions that they actually had to ask to glean that information and they have had experience with it in the past," said NSW Police's Fraud and Cybercrime Squad Commander, Detective Superintendent Arthur Katsogiannis.
"That is why we are saying this particular criminal syndicate had inside knowledge.
"...the fact is many of them had been clued up as to what was required to obtain that information and did a great job, unfortunately for the victims involved, in obtaining that information."
Detective Superintendent Katsogiannis later added: "In most instances they were targeting individuals through these large corporations and companies, soliciting the information from those companies to actually obtain the personal details of the individuals and then use that information for identity takeovers and for opening of fraudulent bank accounts and credit cards."
