Bukkit

BotBeGone is a lightweight plugin that implements a captcha system to catch spam bots. When a player logs in they will be asked to enter a customizable captcha. This captcha can be composed of numbers and/or letters. You can also choose what aspects of gameplay are disabled and which are not.

On first run, Bot Away will generate a config.yml that looks like this:

Length : 5
Use Capital Letters: true
Use Numbers: true
Reset Authenticated On Restart: true
Correct Captcha Message: '&6Congratulations! You passed the Turing test!'
Movement:
  Block: true
  Repeat Message: false
Interact:
  Block: true
  Repeat Message: true
Inventory:
  Block: true
  Repeat Message: true
Placing:
  Block: true
  Repeat Message: true
Breaking:
  Block: true
  Repeat Message: true
Item Dropping:
  Block: true
  Repeat Message: true
Item Pick Up:
  Block: true
  Repeat Message: false
Chat:
  Block: true
  Repeat Message: true
Commands:
  Block: true
  Repeat Message: true
  Allowed Commands:
    - login
Authenticated:
  - superckl

The first few are self explanatory, but "Reset Authenticated On Restart" means that the plugin will store the authenticated players in memory. This means the list will reset every time the plugin is reloaded. If this is false, the plugin will resort to the "Authenticated" list at the bottom. This list survives restarts. *Warning* If you have several hundred players on at any given time, this list can grow quite large and may start to cause lag.

Each entry (Movement, Interact, etc.) has a "Block" field. This means the player will not be able to do that action until they are authenticated. "Repeat Message" means they will get a message to enter the captcha whenever they do that action. I strongly recommend you leave it off for Move (The player will be spammed whenever they move).

Under Commands, you will see an "Allowed Commands" field. Commands listed there will be allowed through the captcha system. This is for plugins such as xAuth.

superckl is my ign, so feel free to remove it if you want, it's just there as an example.

Bot Away also supports permissions!

botbegone.help - Gives access to /botbegone help
botbegone.reload - Gives access to /botbegone reload
botbegone.lock - Gives access to /botbegone lock
botbegone.lockdown - Gives access to /botbegone lockdown

You can do "/botbegone help" will give you a list of possible commands. /botbegone reload will reload the config file for Bot Away. /botbegone lock {playername} will force a player to enter another captcha. /botbegone lockdown will force all players to enter another captcha.

As I said before, this plugin can help stop most, if not all, spam bots. I actually use a simpler version on my server.

Feel free to send me messages about any bugs you find. I will try to fix it as soon as possible.