Griefing

Griefing is the overall term used to describe deliberate acts that ruin, impair or otherwise negatively impact a player's playing experience.
==Cobble Monsters==
Cobble monsters were a popular method of scaling walls and disrupting enemy factions in 1.0 that involved the use of water and lava buckets at the top of a pillar to create a pyramid of cobblestone. Their common usage heavily influenced the decision to outlaw access to placement of lava on the server. While still in practice towards the end of 1.0, Freddy120 began to crack down on offenders such as AkarloR of Eire.
==Lag Machines==
One example of an effective lag machine is a machine constructed by members of Cadiz, Spain in Version X. It was a grid of hundreds of doors, connected together with redstone and wired to a clock circuit. It managed to reduce server TPS from 20 to 4, resulting in overall poor performance. As a result, all members or Cadiz were permabanned from server.
It can be effectively prevented and combated by alert admins, by performing periodic checks of redstone block placement logs or by disabling redstone processing altogether.