A major international crackdown on websites selling credit card details has seen several top websites taken offline by organised crime police.
More than £500m of fraud has been prevented by the recovery of 2.5m credit card numbers, police said.
Two British men were arrested in Tottenham and Birmingham, and a Macedonian man was also taken into custody. Police said more arrests were expected.
The UK Serious Organised Crime Agency (Soca) worked with teams in Europe, the United States and Australia for two years before carrying out the operation on Thursday.
At least 36 websites were shut down, the BBC reported.
The sites included some using Automatic Vending Carts (ATVs) to sell large amounts of stolen data very quickly.
"Working with the FBI, the BKA in Germany, the KLPD in the Netherlands, the Ukraine Ministry of Internal Affairs, the Australian Federal Police, and the Romanian National Police, Soca has recovered over 2.5 million items of compromised personal and financial information over the past 2 years," Soca said in a statement.
Lee Miles, head of cyber operations for Soca said: "This operation is an excellent example of the level of international cooperation being focused on tackling online fraud.
"Our activities have saved business, online retailers and financial institutions potential fraud losses estimated at more than half a billion pounds, and at the same time protected thousands of individuals from the distress caused by being a victim of fraud or identity crime."
Soca also called on Internet Service Providers (ISPs) to stop the anonymous registration of web domains.
Miles told the BBC that ISPs needed to do more to stop customers "buying websites and using them for criminal ends".