There’s not much to prevent it from happening. They could lose standing in the community. They could be given legal trouble, and they could be attacked in return by people who knew which server owner was responsible. But that’s pretty much it.

There’s also a much lower bar for entry when it comes to running a server. All you need to “be” is technically competent. You don’t need to be very good at security, and you don’t need the temperament of a reasonable person.

And when that’s the case, data might be leaked even indirectly.

Two Mastodon examples come to mind.

• One administrator shut down their servers after being accused of transphobia. They could have done anything after having a bit of a public meltdown, so that was the best case scenario.
• Another server administrator was raided by police, and all the contents on the server were made accessible to them.