@botwikidotorg about moderation: I have 2 implementations going on, one at @buzzworkers using Wordpress, another at @EUwatchers using wordpress & my own personal using @WithKnown.
- on my personal site (here) I have never faced serious Spam. sometimes occasional "paper.li" auto-generated tweets but that's about the most serious I have gotten here. right now Known does not have yet a way to moderate spam, but there is an Akismet plugin for Known installed here just in case webmentions spam is going to take off.
- Now on the wordpress indieweb sites I run I have seen more "spam" then Known. first the typical linkback kind of spam but also social media spam and the usual wordpress comments kind of spam. the IndieWeb implementation on Wordpress is good regarding moderation, basically webmentions are like any comments: they can be moderated before publish or can be configured to be automatically displayed.
right now to my experience on these WP implementations the biggest vector of Spam is classic wordpress spam, not specifically webmentions spam.