An international police operation has dismantled an online spoofing service that allowed criminals to steal more than 120 million dollars from people.

iSpoof, which displays a message stating that it has been seized by the FBI and the U.S. Secret Service, offered "spofing" services that enabled paying users to mask their phone numbers with one belonging to a trusted organization.

The users were able to impersonate an infinite number of entities for financial gain.

The website's suspected administrator was arrested by the Metropolitan Police and charged with fraud. There will be a court appearance in London on December 6.

According to the Met Police, iSpoof had around 59,000 users and caused around £50 million of losses in the U.K. The average amount of money stolen was just over $10,000.

According to Europol, the service's operators made an estimated $3.8 million in the last 16 months.

A further 100 U.K.-based users of the iSpoof service were arrested by the Metropolitan Police because of the discovery of payment records on the site. In a joint Ukrainian-U.S. operation earlier this month, the site's infrastructure was seized and taken offline.

Potential victims can be contacted via text on Thursday and Friday by the police. The Met will use the text message to encourage victims to visit their website.

The Metropolitan Police Cyber Crime Unit went after the users of iSpoof instead of just taking down the website and arresting the administrator. We have your details and are working hard to locate you no matter where you are.

FBI seizes notorious marketplace for selling millions of stolen SSNs