[corybrown]

15+ years later, we will try to standardize something that's barely used anymore

> This is a similar "Linkback" mechanism to the ones of Refback, Trackback, and Pingback. It uses a different protocol, though, and thus should be discoverable through its own link relation type.

[miohtama]

Pingbacks, during the WordPress glory era, where killed by spam. Everything that is unauthenticated or weakly authenticated messaging without centralised censors will turn to a spam channel. How do new protocols avoid this?

[CarelessExpert]

At minimum Webmention requires the originating site to be hosting content that actually references the mentioned page.

Spammers would then have to host the location where the spam is located, and then you can block them.

But, frankly, this isn't actually a solved problem yet. I'd imagine building a spam blocking engine on top of a service like webmention.io is an obvious next step if/when this becomes an issue.