Probably not a conspiracy as such
But one of my favourite mysteries anyway. The 'Bloop'.

en.wikipedia.org/wiki/Bloop

For the uninitiated; an ultra-low frequency and extremely powerful underwater sound detected by the U.S. National Oceanic and Atmospheric Administration (NOAA) in 1997. The source of the sound remains unknown. While the audio profile of the Bloop does resemble that of a living creature, the source is a mystery both because it is different from known sounds and because it was several times louder than the loudest known, recorded animal, the blue whale. Some have speculated that if it is a living creature, as it does appear to be, it would have to be several hundred feet long.
(TheManWithThePlan cussed your mum on, Thu 8 Dec 2011, 11:43, 3 replies)

I remember reading about this in the papers
1997? Whoa. Can't remember which newspaper it was, but they reported that the likely source of the sound was 'undiscovered sea monsters'.

It made me happy to think that human beings still consider any large, undiscovered creature to be a 'monster'.
(leviticus no longer likes the cut of your gib on, Thu 8 Dec 2011, 11:48, closed)

^What Special Needs Andy said^

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Thu 8 Dec 2011, 11:55, closed)

Cthulhu!
He comes!
(Dildo Bugger destroyed a ring on, Thu 8 Dec 2011, 12:23, closed)