On June 19th 2009, a mysterious YouTube channel appeared called "Marble Hornets". The "creator" of the channel , Jay, had gotten his hands on the tapes of a film project his friend was working on. His friend stopped the project and quickly moved schools. When looking through the tapes, Jay found that the tapes where largely not about the film project, but was Alex, Jay's friend, recording himself and his encounters with a mysterious and faceless creature called the "Operator".
The web show Marble Hornets is based around a mysterious figure called the "Operator", which is heavily based on the Slenderman. Though, the "Operator" is only the tip of the iceberg. There are the Operator's minions called "proxies" that do the dirty work for him, who are just as scary as the Operator himself.
So what makes the show so scary? What makes Marble Hornets different from any other horror story you've seen or read? It's the fact that the show denies its existence as a show. Apart from the original Marble Hornets YouTube channel, there is a YouTube channel called "totheark" that is from the perspective of the Operator's proxies, where they uploaded cryptic videos that responded to the Marble Hornet's entries, as shown here:
The show also had a twitter account connected to it where the main characters would interact with fans and keep fans updated on the story in short blurbs where a whole video probably wasn't needed.
This style of film making has inspired other film makers to create similar web series such as TribeTwelve, Everyman Hybrid, Meatsleep, ACVE 16, and many many more. So if sometime, you are looking for a little spook late at night, check out Marble Hornets or any others listed above. You won't be disappointed.