A case was registered against a resident of Karaikudi in this district for an alleged 'derogatory and threatening' tweet against former union minister P Chidambaram and his son, police said on Tuesday.
The Karaikudi police registered the caseagainst the man hailing from the town fortweeting against Chidambaram and hisson Karthi Chidambaram.
While Chidambaram is a Rajya Sabha MP, his son represents Sivaganga constituency in the Lok Sabha.
The FIR was registered based ona complaint by A Palaniappan, a local Congress functionary.