Incident at Dulce Base: The largest underground alien base.

People tend to recall random events that happened or someone close when they think about UFOs or alien lifeforms inhabiting this planet.

This photograph usually holds the caption: Dulce Base Security officer Thomas Costello leaked these to the public He and his family are missing & presumed dead by the public. Source: The Black Vault

Even if you are not directly involved with extraterrestrial life, you may already be aware since significant inside information can't be hidden for very long.