Dark Net

The Dark Net is a section of the internet mentioned in Grand Theft Auto V and Grand Theft Auto Online.

Description
In the heist setup mission, Humane Raid - EMP, Agent 14 mentions that they found out about the EMP when the military tried selling it on the "Dark Net".

The Dark Net is a reference to the real life "Deep Web", a section of the internet that is hidden away, and contains many illegal activities, including drug dealing and arms smuggling. It is only accessible through special browsers, the most notorious being the Tor Browser.

The fact that the military is selling the EMP and other military equipment on the Dark Net is likely a reference to the arms smuggling located on it in real life.