Bookbanning

Bookbanning is a practice often carried out by Spawnfags to "ban" unsuspecting victims. To bookban, you need to fill three shulkers with banbooks, all stacked to 16. Banbooks are books with obscene amounts of characters inside of them, and they should not be confused with Dupebooks. Banbooks are often renamed to other items that stack to 16, like enderpearls. So if you ever get shulkers upon shulkers of enderpearls, place them all down or throw them away. When one has three ban-shulkers in their inventory and they open a chest, ender chest, or any other container block, they get kicked out of the server. When they then rejoin, they'll get kicked instantly again. Bookbanning was first discovered by Jumbo, but then popularized by _Prismary.

Hausemaster stated in early June 2019 that bookbanning would be fixed, and that anyone who is book banned can login again. link.