Minecraft server question? Is this illegal?

[Tyler]

So a friend got an Owner of a minecraft server to op her by tricking him into thinking she was a famous youtuber (or at least that's what I think happened). So we banned the owner and some of the staff and kinda took over the server. We didn't use any hacks, so would this be illegal?
*cough troll* Anyway I do have my owner server bro. The owner was a jerk. I told her we should stop.
Also I know it was a dick move, I feel bad about it on my part.
Agreed. But I really need to know if this is illegal. It doesn't seem like it would be, but I need to know.
Mojang doesn't host servers...
Anyway we didn't exploit the software with hacks or anything. My friend just convinced the server owner to op her. I wouldn't think there's laws about who you can and cannot ban on minecraft

[Peter Griffin]

Thats an insanely douchey move on your part, unban the admin. Yes, the admin is insanely dumb, but this is so mean, you dont even know how much effort it takes to run a server, how much money, tears, sweat and blood. Its exhausting and you just made this persons life hell. I also tracked your IP so I have your phone number, and I am considering reporting you to the cops about this. Extremely unethical on your part.

[The Dude]

If the owner knew 10% of what he was doing, he would know that you can ban/ unban anybody in the text files that are made by the server.

[Manjit K]

Actually if they have set up thier server through Mojang and get paid to keep it up, you will be charged.