Four people have been arrested on suspicion of conspiracy to defraud, conspiracy to launder money and possession of an explosive.
The two men and two women were detained as part of an investigation led by the Metropolitan Police's new Cyber Crime Unit.
The men are currently in custody at a central-London police station and the women have been bailed to return on a date early next year.
More top news
Pilots with a history of depression should not be banned from flying, a leading British psychiatrist has said.
Parents have been told by teachers they'll be reported to police and social services if children to play Call of Duty or Grand Theft Auto
TV presenter Alice Beer has said the pair received similar kidnap and rape threats just weeks before the Crimewatch star was murdered.