Many times it becomes tool at the hands of Cong and try to save the Govt by threatening opposition with cases. Same thing happened with DMK. All was well till the party supported Govt but the moment it snapped ties, Cong unleashed CBI. CBI became laughing stock when it raided Stalin’s house in search of a missing car! when it had many more important duties to do.
In the similar manner Mayawati,Jayalalita,Lalu Prasad,Mulayam Singh is tamed to support when in need. Even YS.Jagan cases are due to his opposition to Cong.