The Solana Foundation has removed over 30 validator operators from its delegation program due to their involvement in malicious sandwich attacks against network users. A sandwich attack is a type of front-running exploit where an attacker places two transactions around a victim’s transaction to manipulate the market to their advantage. The expelled validators collectively hold 1.5 million SOL, representing about 0.5% of the planned stake. Many of the removed operators are Russian. On Sunday, a governance draft was posted on Jito's forum discussions to blacklist validators using private mempools. On Monday, the Solana Foundation removed operators from its delegation program for sandwich attacks. This decisive action underscores the foundation's commitment to maintaining the integrity and security of the Solana network.