Such as storing, uploading, downloading and serving transactions in a specific particular way called blockchain or distributed ledger. They have also explicitly forbidden storing blockchain data on their servers and having anything auxiliary related to it.

It is obviously a hostile language created by lawyers who did not spend much time researching the subject.

Of course it's unenforceable in practice and that is why a hefty chunk of Ethereum nodes are hosted on Hetzner for years and years with no problems.