Multi-Streaming, often shortened to Streaming, is the practice of consuming multiple streams of content at once. This was altogether not impossible on earlier interfaces for Internet, but the innovation of Direct Neural Interface ("DNI", Dini) technologies and Switch To Crystal Nanotubule Data Transmission streamlined the practice and increased bandwidth efficiency to the point of revolutionizing it.
Now, instead of sitting in a room playing a video game, communicating in various audio & text streams to friends, and watching a movie or show in a Picture-in-Picture display, a user could be anywhere with Wi-Fi and do every one of these things in their Head Computer. The ease of use led to increased volume of streams per user, until it became commonplace to consume around a dozen streams at once.
Those who engaged in patterns of maladaptive addiction to Multi-Streaming became known as Goons, a pun based on multiple "Streams" feeding into a (La)goon.