I don't think Frank Costello ever gave the Feds info, maybe a slip of the tongue right near the end of his rule, but not like how it is described as above. Luciano gave up some information to the cops before being made. Carlo Gambino is suspected of giving information to the FBN during the 1940's and 50's. Joe Colombo is suspected of giving information on some of the guys with the Gallo brothers. I am sure there are some back in the day before they were made. Once made they never mentioned the Italian organizations names, but other criminals not affiliated with them. I don't believe 50 percent, more like 5 percent, more when you include associates.