You're not supposed to get into Super Secret Settings. It's just a troll button. Why hasn't anyone realised the you either have to modify the game or work at Mojang in order to access it? Anyways, what's inside Super Secret Settings is the option to go Upside down, nothing too special.
If they really did OP then selves then make sure it's true, check the command logs and see if they did something like this: ".Op [Insert Griefer's Name here" but if you see this: "/Op [Griefer's Name Here]" and look at the person who did the command then ban them, they problebly Opped the griefer and unbanned him. If the griefer did op them selves then get onto the consoles and IP ban him. If There is someone alse who is OP on your server who is betraying you, then ban them too. Simple.
If something like this happens then it maybe client-side for you, Check what MC-version you are using, if you are using an out-dated version such as (Beta 1.8, 1.0 or The Cave game Version) Etc., or if you're using an unstable snapshot then that might be the case. I'd suggest changing your Minecraft version to the latest (If it's not a snapshot) and changing it back. or maybe just wait a day or so.