While I were in a player using Minecraft Bot tried to use bot commands. He tries to use cuboids as a guest this way.
They look like !cuboid and it will publicly available in chat. The player opens a separate account for the bot. And the player(dingusnin) types some commands. Then the bot(DaCookieDingus) will respond very fast, like Dankirk. If you see something like this freeze the command typer, ask him to unload the bot. When he unloads the bot(DaCookieDingus) account will exit. Doing /info to the command typer can be an easy way to spot the bot. When the bot comes again kick him. When comes another time ban both accounts; if possible do BanAll.
This is against the rules because:
The only form of gameplay assistance allowed on the server is that provided by the World of Minecraft Client