Webster's dictionary defines subliminal as "existing or functioning below the threshold of consciousness." Subliminal messages are messages that are hidden inside images, music, or videos with the intention of provoking the recipient's subconscious mind into processing some thought without their conscious mind being aware of it. Subliminal images contain subliminal messages which, in essence, without your knowledge, cause you to think or do something you would not have done otherwise.
1: Disney's Lion King

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Although technically not an image, this frame from Disney's animation "The Lion King" is perhaps the most famous and disputed subliminal message ever discovered. When Simba sends up a dust cloud the letters "S-E-X" can clearly be seen when the movie was paused. Although the films animators defended the dust as spelling out an abbriviation for "special effects", the formed letters were edited out all the newest versions of the movie in order to avoid further conflicts over the issue. Disney is notorious for the many sexually natured subliminal images aimed at kids uncovered in its works.
Movie Posters
![[sex+subliminal+Message.jpg]](http://4.bp.blogspot.com/_BaWeTAWt3VI/RpjMZO5tJII/AAAAAAAACV8/hE9dMA8XczM/s1600/sex%2Bsubliminal%2BMessage.jpg)
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Three fantasy movie posters, and yet... This is by far the most obvious location of hidden naughtiness. I mean these had to either have been arranged like this as a joke by some employee or are truly a very interesting act of chance.
Flowers

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At first glance we see what appear to be several pretty flowers. However, looks can be deceiving, a second look at the negative space in between the three flowers uncovers the three letters which spell out America's dirty little secret.
Skittles Bag

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Put together the "S" in the red skittle and the "eX" in explosion and what do you get? Thats right, even candy promotes sex now.
Pepsi Cans

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In the summer of 1990, in honor of the 4th of July, Pepsi began to distribute limited edition "Cool Cans" as part of a promotional campaign. A lucky drinker found an unexpected message, hidden in the new neon design, when he stacked two of the new cans atop each other.
Fifty Rupee Bill

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These 50 Rupees from the Seychelles might not be able to buy sex, but they sure can stick it in your face. If you look close, and tilt your head to the right, you will see that the palm trees to the right of the woman spell a word I am sure you can all guess by now. Hint: the top two leaves form the letter "S".
X-Men Comics

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This comic from X-Men was one of many like it, part of an issue in which the artist chose to hide the word sex on each and every page. In this image, the word sex stands out because it has been colored bright red. The uploader of the comic has also circled it for those of us who cannot find it on our own.
Author's Note: The bias nature of this article (which makes it sound like a conspiracy) was used in order to assertively present a single point of view and is not a reflection of my own personal opinion as to the legitimacy of these images or who put them there and why. Hope that'll answer some questions. Feel free to share your own opinions.