The "Jeff the Killer Jumpscare" became a staple of the early 2010s "screamer" era. These were bait-and-switch links or videos designed to trick users:
The jumpscare itself became a viral weapon used in pranks throughout the early 2010s. It typically appeared on "troll" websites or hidden within seemingly innocent links, such as a fake Minecraft site or YouTube "scare" videos. The SCARIEST Jumpscare - Jeff the Killer: Horror Game