Federal employees across the country, many of whom have worked from home since the COVID-19 pandemic, were back at agency offices Monday under President Donald Trump’s return-to-office mandate. Billionaire Elon Musk,

The president said Elon Musk’s Department of Government Efficiency has found “hundreds of billions of dollars in fraud” as he suggested that federal paychecks are going to nonexistent employees.

Multiple major agencies, including the FBI, State Department and Pentagon, have directed employees not to respond to Musk’s email.