random people joining my private server

[Mike350Z]

Hi
is there any way to stop tosspots joining your game? i set a private server and 2 people joined anyway looks like they were modded as could jump higher than the trees and sat on my spawn point laughing and swearing at me in French and playing thomas the tank engine music really loud.
this just confirms why i do not play online games with randoms!!! is there a way to stop this happening as otherwise i wont play it which is a shame as looks good./