The focus on technology here is very important. Right now, there is no way for Wikimedians to control from whom they receive "email this user" emails, or pings through the notification system. We know that both have been, and continue to be, vectors for harassment and trolling. There's never, to my knowledge, been any consideration given to including these features. We keep being told we're going to get this wonderful new communication system called "Flow" to replace talk pages. Features that allow users to control who posts to their "page", or even to let non-admin users remove individual threads or posts from their "stream", aren't included - and I'm not sure they're even under consideration.
Risker