@janboddez
😊 This is clear-cut to me as all users can not be expected to understand that their comment on a social media post will end up on a blog page. Thus this happens without consent as the understanding is not there unless the social media post itself has a disclaimer. That does not mean it's illegal, just that it's not fair to expect that all users are okay with this.
(Full disclosure, I've implemented tools like this in the past with Twitter, pulling in all mentions of a blog post. I also thought it was cool when not fully considering impact and consequences)
The other interesting issue is that automated stuff like this will mean that the blog owner may have illegal content posted to their page through the same mechanism. Comments can mention third parties by name and use hateful language, or include copyrighted material for example.
I think some of the most common errors of assumption when going ahead with these tools are:
1. It's technically possible, so must be okay.
2. Everybody who posts on social media wants to be seen as broadly and widely as possible in any context
3. If you're here you must accept that your content will be republished all over the place
4. Nobody could possibly be harmed
5. It's legal so there is no problem
6. It's cool…