What billionaire got 25 years in jail?

Could you elaborate on the billionaire who received a 25-year jail sentence? Who is this individual, and what specific crimes led to such a severe punishment? Was this a high-profile case that garnered significant media attention, or was it a lesser-known incident? Additionally, how does this sentence fit into the broader context of cryptocurrency and finance, if at all? It would be helpful to have more details to provide an accurate and informative response.