Actually, no, it is more nuanced.
In democratic countries, there are no “rules” for citizens to be concerned about. They are concerned about laws (and other generally binding regulations; but we are getting too nuanced here).
See also the difference between executive, lawmaking and judicial branches. It is divided exactly for the reasons to prevent abuses.
That’s regulation of doing business. Hazard sites are an enterprise in regulated market, and the condition for doing business there specifically is to pay to the state a cut. The blocked sites didn’t, so they cannot do business anymore.
Or more specifically, they are not blocked due to speech, but due to money.
It is actually a law, made by parliament. And if some website thinks that they were wronged, a court can examine, whether they are right or not.
Would you be so kind and provide a link to Czech law regulating this?
It would be interesting, because it would be at odds with ICHR judicatures. There were pretty interesting decisions in the past, of particular interest to you might be OOO Flavius against Russia.
As far as I know, there is none. There is also no way for the affected sites to have their situation examined by courts, a necessary condition, if you want to compare with the previous case.
CZ.NIC admitted themselves, that it was just an informal request and that they thought it was a good thing to do. They actually broke rules.