Capgras delusion is a psychiatric disorder which will make you believe your friends, family or pets have been replaced by identical imposters.
In the 1970's, USSR built a system nicknamed Dead Hand. This system was built to work as a fail-safe in the event of a nuclear strike. It would then automatically launch multiple ICBM missiles to predetermined target without the need for input from a human. It is still running so a computer from the 70's is all that stands in the way of an all-out nuclear war.
A secret organization called Cicada 3301 has on six occasions posted puzzles and alternate reality games (some lasting years) in an attempt to recruit code breakers from the public. It has been called “the most elaborate and mysterious puzzle of the internet age.” People speculate the puzzle to be a recruiting tool for NSA, CIA or MI6. No one has taken credit for it nor has any individual who solved the puzzles has ever come forward.
4Junko Furuta Murder
In 1988, a 17-year-old Japanese high school student named Junko Furuta was abducted and tortured for 44 days after which she was murdered. The murder was perpetrated by four teenage boys. According to their trial statements, the four of them: raped her over 400 times, beat her several times, starved her, hanged her body from the ceiling and used her as a "punching bag", dropped barbells onto her stomach several times, forced her to eat live cockroaches and drink her own urine, forced her to masturbate in front of them, inserted foreign objects into her vagina and anus, shoved a still-lit light bulb into her vagina, set fireworks into her anus, vagina, mouth and ears, burnt her vagina and clitoris with cigarettes and lighters, burnt her eyelids with hot wax and lighters, tore off her left nipple with pliers and pierced her breasts with sewing needles. All four of them were arrested but were only given light sentences for their atrocious crimes because they were teenagers.
Convicted serial killer Albert Fish a.k.a. The Brooklyn Vampire was a child rapist and cannibal, who boasted that he "had children in every state." and at one time stated the number was about 100. He was put on trial for the kidnapping and murder of Grace Budd. He was captured when police investigated a letter that he had sent to the mother of Grace Budd, in which he described how he killed her 10-year-old daughter and ate her. When he was executed, he even helped the executioner position the electrodes on his body before uttering his final words, "I don't even know why I'm here," before he was killed by two jolts to kill him.
6San Fernando massacre
In 2011, Los Zetas drug cartel committed a massacre in San Fernando, Mexico. Cartel members hijacked a number of buses along the highway and kidnapped the passengers. Female victims were raped and able-bodied men were forced to fight to the death with other hostages. They were given knives, hammers, machetes, and clubs. Survivors were recruited as a hitman for Los Zetas. All in all 193 people were killed and buried in 47 clandestine mass graves.
Charles Domery was a Polish soldier of normal build who is noted for his unusually large appetite. He surrendered to the French for food, ate 174 cats in 1 year, often ate 4-5 pounds of grass a day, and after a fellow sailor’s leg was severed, he began to eat it. The prison gave him 10x the rations, but he still ate rats, cats and candles to quench his appetite.
There exists a secret group of investigators named Aerial Phenomena Enquiry Network who specialize in the field of UFOs who regularly contact researchers via letter and cassette tape offering pieces of information, yet never supply contact details. They were active from 1974 to 1990s. They have brought a number of UFO incidents to the notice of the general public when the information was only available to the government.
9Alien hand syndrome
Alien hand syndrome is a rare neurological disorder, in which one hand functions involuntarily, often in direct conflict with the other hand, with the victim completely unaware of its actions. People affected by it can pick things up, throw them and even attempt to strangulate themselves, having to use the controllable hand to restrain the alien hand. There is no known cure for the alien hand syndrome.
Andrei Chikatilo was a Soviet serial killer who killed at least 52 women and children from 1978-1990. In the process of trying to catch him, Soviet police solved more than 1000 unrelated crimes, including 95 murders and 245 rapes. The first time he was captured he was released from custody because his semen type was different from his blood type, which is extremely rare. He even helped police with the investigation at that point. When he was executed, he exclaimed “Don’t blow my brains out! The Japanese want to buy them!”