I talked with Ant a bit about this when I did my training. He said that mods can't do much because of an agreement that was reached. Most of the mods wanted to play survival, and they couldn't do that and moderate hackers. If mods were given /tp and /vanish commands, I hate to say this, but a few of them would abuse them. Thus, the agreement was reached that staff can moderate the chat, and record a hacker if they see the person themselves. But not much else.
However, I've been playing with this idea for some time. What if some moderators gave up there ability to play in the server, and instead can tp and vanish. They would not be allowed to interact with other staff who are playing survival. This way, if someone is being accused of hacking, these special mods can go and investigate. It's just an idea, but it's a possible solution.