Who answers the telephone at 202-555-1030 in 'The X-Files'?

In "The X-Files," the telephone number 202-555-1030 is famously answered by the character of the Lone Gunmen, a trio of conspiracy theorists and hackers. They are known for providing assistance to Mulder and Scully on various cases throughout the series. The number is often used as a plot device to connect the main characters with their unconventional allies.