https://shkspr.mobi/blog/2022/12/the-ethics-of-syndicating-comments-using-webmentions/

Not an answer to the dilemma, though I generally take the position of keeping everything unless someone asks me to take it down or that I might know that it's been otherwise deleted. Often I choose not to delete my copy, but simply make it private and only viewable to me.

On the deadnaming and related issues, it would be interesting to create a webmention mechanism for the h-card portions so that users might update these across networks. To some extent Automattic's Gravatar system does this in a centralized manner, but it would be interesting to see it separately. Certainly not as big an issue as deadnaming, but there's a similar problem on some platforms like Twitter where people will change their display name regularly for either holidays, or lately because they're indicating they'd rather be found on Mastodon or other websites.

The webmention spec does contain details for both editing/deleting content and resending webmentions to edit and/or remove the original. Ideally this would be more broadly adopted and used in the future to eliminate the need for making these choices by leaving the choice up to the original publisher.

Beyond this, often on platforms that don't have character limits (Reddit for example), I'll post at the bottom of my syndicated copy of content that it was originally published on my site (along with the permalink) and explicitly state that I aggregate the replies from various locations which also helps to let people know that they might find addition context or conversation at the original post should they be interested. Doing this on Twitter, Mastodon, et al is much harder due to space requirements obviously.

While most responses I send would fall under fair use for copying, I also have a Creative Commons license on my text in an effort to help others feel more comfortable with having copies of my content on their sites.

Another ethical layer to this is interactions between sites which both have webmentions enabled. To some extent this creates an implicit bi-directional relationship which says, I'm aware that this sort of communication exists and approve of your parsing and displaying my responses.

The public norms and ethics in this area will undoubtedly evolve over time, so it's also worth revisiting and re-evaluating the issue over time.

I'll often share articles to Twitter and don't necessarily do a 1-to-1 match of the syndicated copy on Twitter. Usually I'll excerpt a piece that ends up appearing on Twitter with a link back to the article. I generally presuppose that if they're interested, they'll click through and read otherwise they're bookmarking it or sharing the link with others, so those interactions coming back to the original are always fine with me.

I've done a poor man's version of this on websites that don't send webmentions, but which will let me put the permalink of my original from my site on them (either in a website field, or into the text of the comment and which don't filter out the HTML).

In particular, I've done it on WordPress.com sites and put my reply from my site into their standard comment field and indicated to notify me by email of future comments.

Then when I get the email notification, I can force a manual webmention of the reply and get something back to my website. In practice, it also requires a bit of massaging, but is better than nothing.

I've documented the process here: https://boffosocko.com/2020/01/30/manual-backfeed-in-the-blogosphere/

Sadly, Aaron Davis is right that Facebook turned off their API access for this on August 1st, so there currently aren't any services, including Brid.gy, anywhere that allow this. Even WordPress and JetPack got cut off from posting from WordPress to Facebook, much less the larger challenge of pulling responses back.