Andrew J May, a US Congressman from Kentucky, once gave a press conference where he made it public that Japanese anti-submarine tactics were deficient and resulted in low US submarine losses. Essentially, Japanese depth charges were set to detonate at a depth that was significantly higher (closer to the surface) than the US submarines were able to operate at. Needless to say, this made its way through the press.

While there isn't any direct correlation that we know of, the Japanese did adjust their depth charges (although whether this was due to this information leak or due to their improved ASW experience over the course of the war is uncertain) to a deeper depth, culminating in significantly increased US submarine losses in the later stages of the war. One US submarine commander claimed that May's statement led directly to the losses of 10 submarines and their crew, although this was not demonstrated by any commission. May escaped punishment for this leak but was later convicted for war profiteering.