The Central Intelligence Agency has admitted that it was responsible for at least half of reported UFO sightings in the middle of the last century due to its secret, high-altitude reconnaissance flights.

The 1950s and '60s was an intense period when a number of Americans reported UFO sightings and alien visitations. These sensational events lent cinematic credence to a number of Hollywood space blockbusters, including Steven Spielberg’s "Close Encounters of the Third Kind" and "ET," and George Lucas’s "Star Wars."

Article Link:
http://rt.com/usa/219299-cia-ufo-spy-russia/

I think the tweet was meant as "THE MOST READ website in 2014." Article taken out of context.