I recall that the systemd package maintainer for Debian got death threats. From outside, hearing about death threats related to volunteer work to package software that is given out for free is something I strongly suspect sound unbelievably odd. This happened after gamergate and I doubt anyone got arrested for it.

I recall a few months ago during the days of meeto here in Sweden, children of accused parent got threatened thus resulting in the family leaving the country for a while. No investigation was mentioned in the news article.

From what I see, now is not better than before. Death threats made online/sms/phone is not taken serious unless there is contributing reasons to take it serious.