Blacklist

A blacklist (also known as a blocklist or banlist) is a list of IP addresses and ranges used to ban certain players from playing on a server. Common reasons for a player's inclusion in a blacklist are:
 * cheating
 * player impersonation
 * team killing
 * abusing the master role (prior to version 1.0)
 * unacceptable chat behavior
 * voting spam

Unlike the in-game ban command, the blacklist will keep an IP address banned indefinitely. However, due to dynamic IP addresses, some players may be able to evade their bans. If this occurs, try banning a range of IP addresses.

History
Prior to version 1.0, blacklisting was not a built-in feature. Although masters could ban for 20 minutes, some people made a habit of causing trouble, sometimes grabbing master for themselves so players were helpless until an admin came along. The need soon arose for a more permanent banning method, leading to some server owners blocking IP addresses through iptables, or with a server modification. After the usage of blacklists gained popularity, the amount of abuse dropped dramatically. Persistent abusers could be banned indefinitely, and the possibility of being blacklisted served as an effective deterrent to people considering cheating or causing trouble. Tear you Down! was the first to make their blacklist public, and other server owners would use their blacklist as well, resulting in a domino effect for players blacklisted by TyD!, as long they are not editing their copy.

Criticism
Initially, some people were against having blacklisting as an official feature. Their reasoning was that it wouldn't be completely effective due to dynamic IP addresses, so we'd be better off with nothing.

However, people eventually many people changed their minds once they saw the dramatic difference between vanilla AssaultCube servers and servers with blacklists. Even if all disruptive players couldn't be kept out, blacklisting still helped immensely and reduced the amount of abuse in servers. Server blacklist modifications soon became popular, and it was made an official feature starting with 1.0 Release Candidate 1.

Community collaboration
A public blacklist exists on the official forum, where server owners and normal players can report bad behavior to aid other server owners in keeping their blacklists up to date with the IP addresses of new or existing offenders.