Screamer Culture (very popular in the 2000s) revolves around online pranks such as jumpscares, or being RickRolled in videos, websites, or flash animations.
If you want to know about internet screamers, or shock sites go to the Screamer Wiki. They are basically a whole database about screamers like K-fee, ScaryMaze. There are also shock sites documented like Heyya.org, and 2girls1cup.
Site if you are curious: screamer.wiki
Guy 1: What's the Screamer Wiki?
Guy 2: A magical place that documents screamers.
Guy 3: You forgot shock sites!
Guy 2: Oh yeah! They also made me desensitized. I've seen heyya.org.
Guy 1: Wonderful.
A website link that if opened, an extremely scary image will appear along with a bloodcurdling scream, and the picture will often flash, and it will continue unless the scared person closes the tab. Often used for pranks and jokes by many people.