Congressman May had some loose lips, and inadvertently informed the Japanese that their depth-charges were missing American submarines:
However, the information from May was reported by the press. Would gossip on a local level by civilians reach enemy intelligence? /u/the_howling_cow has at least one example where German spies are present in the U.S., in Were there actually these spies and did these spies cause harm to the allies?
Here, /u/white_light-king provides a broader answer to your question. And finally, /u/Kiltmanenator claims here that the propaganda was meant to prevent discussion of succesful enemy attacks, thus preventing a dip in morale.