Hausemaster stated in early June 2019 that bookbanning would be fixed and that anyone who is book banned can reconnect again.
Bookbanning was used by The Book Club to book ban over 400 newfags in October 2019 using "chambers" which had the same design as trapped nether portals, except they had dispensers that dispensed book ban shulkers to the new players, instantly updating their inventory to ban them.
It was also possible to kick players back into the queue when killing them by shooting a bow while having a bookban in the offhand. It was also possible to kick every player off the server when killing them using a ban book. Hausemaster would later disable death messages as a temporary fix. Death messages were disabled for a while.
Bookbanning was patched by Hausemaster but it took away the functionality of .peek and preview, popular hacks that allowed you to see the contents of a shulker box without opening it.