The case fell through as the complainant didn't identify the accused in the court.
According to the police, Lakshman Karan, Hassan Sheikh and Javed demanded 'hafta' of Rs 25,000 per month from a bar owner in Dharavi in February 2011.
The first time the bar owner didn't entertain them, so they went to him again and threatened him with a revolver.
On the owner's complaint, police booked them under stringent MCOCA.
However, during the trial, the complainant didn't identify any of the accused in the court, said defence lawyer Swapnil Dighe.
"They just produced a list of cases against Karan without any case papers," said Dighe.
Accepting the defence's arguments, special judge S L Anekar acquitted the trio.