The way The Operator was created is never revealed because the makers of the series say that it is so mundane that it takes all fear away from the character.
The word "Bone" is spray painted in every abandoned building used in the film. The crew has stated in an interview that they do not know who has done this.
Marble Hornets is considered one of the "Big 5" series based around the Slender Man, along with EverymanHYBRID, Tribe Twelve, The Andersen Journals and Dark Harvest. However, all of these series, except Marble Hornets, have crossed over with each other at least once, meaning that Marble Hornets is the only "Big 5" series to exist in a different universe to the others.
Entry 22 was considered the hardest Entry to film, as they recorded the action on the hottest day of the year. Everybody rode home in silence and anger due to how unbearable the heat was.
During Entry 72, the crew only had one day to film in the house that belonged to Alex in the series due to time restraints from the people living there, so they really had to pull the Entry off in one take. And luckily, it worked out, as Entry 72 is notoriously the most terrifying entry in the series.