While the number of cryptocurrency-related complaints to the FBI - 69,000 - accounted for just 10% of all financial fraud complaints last year, they represented 50% of total losses. The likes of bitcoin and ether are used in a host of frauds, although investment scams dominate, accounting for around 71% - $3.9 billion - of all crypto losses. Call centre frauds, including customer support scams and government impersonation scams, accounted for about 10% of crypto losses. People over 60 filed the most complaints about crypto scams, reporting the most losses - over $1.6 billion. California saw nearly double the number of complaints of any other state. Michael Nordwall, assistant director, criminal investigative division, FBI, writes in an FBI report: "The decentralised nature of cryptocurrency, the speed of irreversible transactions, and the ability to transfer value around the world make cryptocurrency an attractive vehicle for criminals, while creating challenges to recover stolen funds."