Answer
The SBU, Ukraine's security service, took legal action against Kolomoyskyi in 2023 by arresting him. This move was made in response to Kolomoyskyi's alleged illegal activities, such as large-scale embezzlement and abuse of power during his tenure as governor of the Dnipropetrovsk region. The SBU's arrest of Kolomoyskyi signals the government's commitment to combatting corruption and enforcing the rule of law, even against powerful figures.