Ethics of Shadow Banning

Just wondering what everyone's opinion is of websites blocking a person's communications on a platform without ever telling that person why they have been banned, or that they are even banned to begin with!

Is this an ethical practice? Does it make sense? Are the people behind it not-so-secretly suffering from a little man syndrome? Let's have a fruitful discussion :)

Secretly banning someone from communication is a terrible thing to do!

Ethical counter-questions:

1) read the ToS?
2) why acting against the ToS?

@bunyip , it should be When you pay them money they never ban you, when you don’t pay them money and your account is left there doing nothing, they secretly stop you from playing games and all forms of communication is disabled.