I'm in the US. Your idea violates our justice system's notion of transparency, and it's one I agree with wholeheartedly. Things are different sometimes in cases where the charges involve sexual violence and/or minors, where courts have upheld that the potential damage of publicly naming the victims was worse than the potential damage of not allowing the defendant to publicly counter the accusations. See for example: https://www.gdnlaw.com/blog/internet-law/anonymous-lawsuit-t...

So in the US, at least, if you're going to sue someone over IP violations, you should plan on your identity being made part of the public record. As a country we're pretty adamant about that. It's a feature, not a bug.

I'm including DMCA notices in things I believe should be -- must be -- transparent. They're legal filings after all, strongly implying that if you don't comply, you're about to be sued. Your proposal would allow, say, Oracle to hide their identity if they were filing a complaint against the Linux kernel so that they could get the benefit of launching a legal salvo without the reputation hit for having done so. I believe that's far more unfair, and more likely, than your scenario.