Help hacks

I am creating a public server and I enter and I use hacks in his ship had thousands of materials.
Exste some way to avoid this type of hacks inside the server

 

Simple.
Make some rules in the server setting that prevents players to go in admin mode.
And by the way, this isn't hacking, it's perfectly doable in the game as long as you got access to the command console, from which you can do various things
I'm guessing that the player you're talking about has used the /spawnitem command

 

You can't. They'll just spawn the stuff in singleplayer and carry it over.

 

Then seek honest players

 

There is no way to avoid it? He did that

 

Kick them/ban them if they do it again, but I'd suggest a warning before