Backdoors are events on 2b2t when a player, or a group of players, bypass 2b's normal operations to gain access to exploits in which the particular players can abuse. Currently, there have been three major backdoors in 2b's history and all of them have been patched by Hausemaster.
First Backdoor (Popbob's Reign of Terror)
The first major backdoor of 2b2t, also known as the Dark Times and Popbob's Reign of Terror, has had two intervals. The first interval of the backdoor began sometime in December of 2011 and ended in January of 2012. This is when the notorious popbob became one of the most feared players on the server due to his iconic thunder hack. The thunder hack operated as a sort of tracking device that tracked where lightning would strike. The mechanic of lightning in minecraft only works around chunks that are being loaded by players. By tracking the lightning, popbob essentially was able to track players in a span of months, weeks, or even days and found and destroyed several bases. Popbob, during this first interval of the backdoor, also had access to creative mode, in which he gave to many of his fellow facepunchers, including xcc2, policemike55, and others. This access to creative mode and the backdoor allowed for the creation of Ziggy Town's bedrock comet and Plugin Town. Hause eventually ended this backdoor interval by removing Popbob's access to some of his powers and creative mode.
Despite the first interval ending, popbob continuously found new exploits and still had access to his thunderhack, which brought about the second interval that lasted from January, 2012, to May, 2013. Popbob also made himself invincible with his backdoor powers, allowing him to kill any player he encountered. Accounts have stated that popbob's sword swing was so fast, that you could barely see his arm or sword. Popbob also used his backdoor access to create hacked items. Eventually the backdoor was patched by Hausemaster, disabling thunder from 2b2t for more than five years in the process. Popbob eventually took a break from 2b when he logged against Third Incursion members.
Second Backdoor (The Arms Race)
The second major backdoor of 2b2t occurred during December of 2013. The backdoor involved iTristan and Pyrobyte in which they used their excessive knowledge of Java to create a plugin. They used this backdoor plugin to spawn in several hacked items such as player heads and the infamous 32K weapons, which started the Arms Race. They also used it to get to the world border.
Third Backdoor (The Hacked Account Crisis)
The third major backdoor was probably the most severe backdoor to this date and occurred sometime during the end of 2015 and ended in April, 2016. The backdoor involved the hacking of georgebush420's OP (operator, but hell, can be called overpowered) account and the use of the /a exploit in which allowed players to triangulate people’s coords, causing the destruction of several bases. The group involved used the account to grief bases, create more hacked items, and duplicate their 32K weapons. The backdoor was patched when Hause and George gained the account back.