Earlier quoted context omitted.
This happens literally all the time with Hetzner, I can't tell you how many times I've heard some variation of this story (or seen it here on HN), but they're cheap, and most people aren't going to find the people complaining online about it even if they do actually try to find out more about the company, so I'm afraid it hasn't hurt them much.
They are great for throwaway hobbyist side projects where you don't want to worry about AWS billing horror stories or more expensive offerings like Digital Ocean or Linode. I would not recommend them for a serious, money-on-the-table business.
* crypto mining (I used it when it wasn't causing much trouble but I noticed my nodes were constantly attacked at a ratio I newer saw for other servers); IIRC Hetzner's current ToS forbid crypto mining
* things in legally grey area which might be legal in some places but not so in others, especially in the EU
* protect your servers well; if you become a victim of an attack and your servers will start attacking other, Hetzner will isolate them and notify you so that you can solve the problem
Other than that, the only problems I had in the last 15 or so years are failing bare-metal components that they promptly replaced, that's all.