The Department of Justice said Thursday that it has tapped a prosecutor known for his efforts against digital criminals to lead the agency’s newly formed cryptocurrency enforcement team. Also included in the department’s news release was the announcement that the FBI will be putting together a unit to pursue illegal activity on the blockchain. Cybercrimes prosecutor Eun Young Choi is well-known for leading the legal assault on a prolific Russian hacker accused of siphoning data from a dozen U.S. companies and more than 80 million bank customers. In its statement, the Justice Department said that the FBI’s “virtual asset exploitation” unit would be made up of “cryptocurrency experts” who would analyze the blockchain and innovate “to stay ahead of future threats.” The unit’s formation comes in the wake of the Justice Department’s seizure of a cache of bitcoins, now worth more than $4.5 billion, from a rapping tech entrepreneur and her husband.