This is a server with griefing / raiding enabled, as well as you can tp to whoever you wish, regardless you think them being friendly or not, and quoting from the rules, they state that "TPA Killing/Trapping is allowed.
It's up to you whether or not you make or accept teleport requests. Use the TPA system at your own risk, make sure you trust the players you are teleporting to. If killed and/or your base gets destroyed, its your fault."
This means that it is your responsibility to trust whoever you wish to.
You should know from now on and learn whom is deem trustworthy or not, with time, just don't attack anyone personally, because this is a game and should always be played as one, that's the challenge there is, with time, you'll learn all about it. o/ See you soon