I just had a thought like "What if some UFO aduction experiences people claim to have are actually people being kidnapped by the CIA" 
The kind of stories I'm thinking about often go like: "I was driving on an empty road in the middle of nowhere. I saw a bright light," and then either "I remember nothing but had lost time" or "I remember being experimented on by aliens and then put back in my car."
My tinfoil hat side is thinking like, these stories started happening around the time the US admitted to experimenting with abuse, torture and psychoactive drugs in Project MK-Ultra. Alien abduction stories were the most prevalent during this time. (CW: Just a heads up. If you want to read the rest of this post or anything else about MK-Ultra, be warned that it's pretty horrible, and involves some of the most disgusting torture I have ever read about. Death to America.)
Of the surviving documents released to the public about MK-Ultra, the CIA admits to: "kidnapping people it deemed "expendable" to undertake various types of torture and human experimentation on them. The prisoners were interrogated while being administered psychoactive drugs, electroshocked and subjected to extremes of temperature, sensory isolation and the like to develop a better understanding of how to destroy and to control human minds."
Part of me wonders how many of these alien abduction stories are just people being kidnapped, drugged with powerful hallucinogens, experimented on and then released with the suggestion conditioned into their mind that it was aliens.
The most famous alien abduction story is that of Barney and Betty Hill, an interracial couple that were both civil rights leaders, definitely people that the CIA would want to fuck with, especially during rising tensions with the Soviet Union, the US government was suspicious of minorities and anyone interested in their rights.
Those conspiracy theories come from the abysmal track record of the U.S. medical system. From over-prescribing opiates for kickbacks to the Tuskegee Experiments, the U.S. medical industry has been responsible for countless horrors over the years. People remember when their relatives, family members, or close friends died of opiate overdoses, and that mistrust extends itself to the rest of the industry. The only reason why I chose to get the vaccine was because the companies were hoarding them from the third world, which was a sure sign that it was effective enough to warrant even more racism in medical care, meaning that these evil companies apparently had something to offer.
Add on to this countless crackpot theories allowed to propagate throughout the country, like "vaccines cause autism" and "china steals organs", and you get a recipe for a population that has zero trust in companies like Pfizer and J&J.