I think in Europe the domain name providers (or would one rather call them resellers ?) switched to redacting all private domain holder information since a few years. It was actually quite horrible like it was before, so much email spam, a free ticket for spammers to put all those Whois information wide open on the Internet. Some providers, like Greenhost in NL, provided Whois masking (cloaking ?) for customers paying a bit more.

You are not wrong, but there is a reason that identification requirements exist for domain registration. In any case, however, at the end of the day a person who registers a domain through Njalla does not have ownership of the domain. This is not an insignificant fact no matter how you spin it. It's not your domain. You're blindly trusting someone whose credentials are to have pirated movies two decades ago with something that might potentially be tremendously valuable, if to no one else but yourself.

Unless you're literally doing something illegal, choosing Njalla over a regular vendor offering WHOIS privacy is to move beyond privacy consciousness into the realm of paranoid recklessness.