Community mention spam from Microblogs

[julian@activitypub.space]

So, this meme.

tl;dr Mastodon users occasionally spam mentions and Lemmy (and probably Piefed) ingests them all and makes the post across all of the mentioned communities.

Sucks, right, because on the theadiverse, you're not actually able to do that so easily.

Basically, it's because Mastodon mixes mentions with addressing. Every mentioned person gets addressed, even though sometimes you don't mean for it to go into that community.

So what if Lemmy, Piefed, Mbin, and NodeBB made it so that only the first matching community gets the post? We can already tell which posts come from threadiverse software and which don't (because we use audience, Mastodon doesn't.)

Just an idea, I can't speak for the other softwares.

[ptz@dubvee.org]

So what if Lemmy, Piefed, Mbin, and NodeBB made it so that only the first matching community gets the post?

Not sure about the others, but doesn't Lemmy do that already (only applies the first matching community)? I've been out of the loop for several months, so maybe it changed, but I thought it already did that?

[julian@activitypub.space]

If it's not an issue currently, then that's even better 👍

At least on NodeBB we only post to one community, but it'd still happen even if other communities on other instances were mentioned first, so it could still be abused.

E.g. mention four communities on four different instances, get posted to four communities.

[mesamunefire@piefed.social]

Can I get an example post or something? Im not seeing the issue?

[silverpill@mitra.social]

Sucks, right, because on the theadiverse, you're not actually able to do that so easily.

Sounds like an unnecessary limitation of threadiverse software. Why limit a post to only one community? That doesn't make any sense.

The person who made the post with multiple mentions clearly did it intentionally, and I would do the same because for every topic I am interested in there are 4-5 groups on different servers.

Every mentioned person gets addressed

In most cases, this is what a user wants. Some platforms support silent mentions, though (Friendica, if I remember correctly).

hashtag / community tag soup

I think this should be viewed as a moderation problem, not a protocol problem. If you don't want to see mention soup, just limit the number of mentions per post on your instance.

[cochise@social.subversida.de]

@silverpill @julian @fediverse I can see a potential spam vulnerability here, but not a huge problem. In threadverse we use cross posts to reach multiple communities.

[bjoern_tantau@swg-empire.de]

Meh, I don't see this as a problem. People already crosspost into multiple relevant communities. If anything doing so with one post is a feature that's missing from Lemmy/Piefed. Or is it missing? I'll try posting into multiple communities after this comment.

It seems to me that your problem is more aesthetic in nature. Maybe ask your favourite UI to make a feature to hide mentions and hashtags that are alone on their line.

[bjoern_tantau@swg-empire.de]

Just tested it. A Lemmy-Post is only created in one community, even if other communities are mentioned.

An external post (in this case from WordPress with the Activity Pub plugin) is only posted into the Lemmy community that is mentioned first.

[pamasich@kbin.earth]

So what if Lemmy, Piefed, Mbin, and NodeBB made it so that only the first matching community gets the post?

I'm pretty sure Mbin already does that with sorting posts into communities based on their hashtags. Does it not do it with mentions too? I can't really test it since 99% of federated posts only mention one community, if any. So I'm struggling to find a post that mentions two communities, let alone two that are active enough on my instance to compare them.

But like, is it actually an issue? I always get the impression Lemmy users have more of a problem with the hashtags and mentions in general, not with the fact the post appears in multiple communities. Which would be easily solved by having their instance remove those from microblog posts.

We can already tell which posts come from threadiverse software and which don't (because we use audience, Mastodon doesn't.)

I honestly don't think that's a good way to decide between threadiverse and others in general. There's no guarantee non-threadiverse software won't make use of it in the future.

[pamasich@kbin.earth]

If you don't want to see mention soup, just limit the number of mentions per post on your instance.

Doesn't Mastodon require mentions though to function correctly? Imo instances should just not display leading or trailing mentions / hashtags. That should get rid of the problem without imposing limitations on Mastodon users.

Definitely agree with you on your first two points.

[julian@activitypub.space]

silverpill@mitra.social isn't wrong though, in many cases the posts do mean to be posted in that community.

But it's an expressive thing. I'm able to mention a community like startrek@startrek.website and it won't be posted there, because I'm only mentioning that community.

And yes, Mastodon needs mention spam to function because otherwise people you reply to won't know they received a reply. It's ... an approach.