Subliminal messages are hidden messages placed in advertisements, cartoons, films, music and videos to influence viewers without their conscious awareness. They are inserted by hiding messages in audio, using invisible flashes in movies, or hiding messages in logos and visual materials. Examples include the word "Coca-Cola" written in the One Ring from Lord of the Rings and the word "Illuminati" written on Rihanna's forehead. Product packaging sometimes contains hidden images, like a cross hidden on a tomato. While these messages aim to influence minds secretly, the ethical implications of subliminal messaging remain unclear.