I shared a link from NPR Tiny Desk but there was no image preview or video embed. After investigating this I learned that when you do that, each instance picks up the link and individually retrieves the link preview nearly simultaneously. For gargantuan sites like YT or Reddit, this is a trivial amount of traffic and not a problem, but for smaller sites like NPR this results in a sort of botnet DDOS attack on the site’s servers. More here. Another example here . For that reason, NPR has blocked Fediverse servers like Mastodon.
I have experienced this on my personal server as well (DDOS), but at the time didn’t know why, exactly.
This isn’t the end of the world, but certainly is not great and hurts engagement with the content. Is there a solution for this? Perhaps using some sort of webtorrent service like PeerTube where they just fetch the information from another fediverse server instead of the source server? Maybe fetching embeds client-side? At least that would stagger the requests.
The great thing about this if you run a server, as soon as a user posts a link to some kiddy porn, you not only download it automatically, you distribute it as well. Go-go-gadget-jailtime.
(Actually already a problem with Mastodon federation of image posts, and why I would strongly encourage against anyone in a strict liability jurisdiction from running their own Mastodon server tbh.)
This is no different from how it is already, though. If a user posts a CSAM link, your server immediately visits that link to scrape it, and you suddenly have that content on your server.
Of course, if you have a blocklist of forbidden sites, then your server will know not to scrape that site. And the same thing applies if we allow servers to send pre-scraped metadata. If the incoming message is for a blocked URL, just drop the message and don’t save any part of it.
The only new threat here is for a malicious server operator to modify outgoing messages to include CSAM metadata on a harmless link. However, that possibility already exists with any other content posted on the fediverse. If a malicious server is modifying its own outgoing messages, the only fix is to defederate from it.
Allowing servers to forward pre-scraped metadata to other servers does not introduce any new threats that do not already exist.
There’s no reason to believe that this mechanism doesn’t check for CSAM (I am also pretty stumped that this is actually a problem with Mastodon according to your comment?) . Lemmy had a phase where messed up stuff got federated, which led to @db0@lemmy.dbzer0.com’s implementation of an anti-CSAM tool: https://github.com/db0/fedi-safety, which is based on the CSAM detection tool for the AI Horde: https://dbzer0.com/blog/ai-powered-anti-csam-filter-for-stable-diffusion/ - it’s probably not so hard to adapt for Mastodon too.
If you want to trust a hypothetical “detects CSAM honest” feature with something like this, well, you go ahead.
I mean; just imagine for one moment that lemmy.ml actually is the hotbed of revolutionaries that is going to usher in the Glorious Revolution that it thinks it is; it starts actually moving mountains, politically speaking.
And, some bright spark has implemented the “automatically download and distribute content from unverified sources, protected only by the open-source Kiddy-Porno-Matic Verifier v0.1.23” feature.
If I were Peter Thiel it would take me 5 minutes to start posting links that caused lemmy.ml’s servers to start downloading and then distributing kiddy porn, about 20 minutes to get some tame journalists parked outside the owners’ houses and lemmy.ml’s datacentre, and another 10 minutes to call up the friendly neighbourhood goons in wherever they are located for the photogenic armed raid. And once the “revolutionary leaders in court for making and distributing child pornography” headlines had finished writing themselves, I wouldn’t even worry about whether the court would accept the “but we ran the Kiddy-Porno-Matic Verifier v0.1.23!” defence, because their lives would be over already. No smoke without fire, after all…
Nah. “Automatically download and distribute content” features need rather more thinking through than historically Mastodon et al have given them. They certainly don’t need to create any more.
(And to be clear - maybe Mastodon has fixed some of their underlying problems - I ran an instance a few years ago, and the constant whack-a-mole of blocking actual-Nazi and actual-Pedo instances, and the risk that it could just go ahead and download something to my servers because a user followed the wrong person had me shutting it down not long after. As I say, maybe they fixed that - but this mooted feature would be bringing back the same problem.)
Of course, maybe Lemmy.ml is (a) hosted in a jurisdiction where they don’t give a fuck, and (b) can afford to defend themselves. But this kind of feature will actively work against people who otherwise might host a small instance, and I thought that is what we wanted, not just a few massive instances that can afford to lawyer up.
All, I should say, IMHO of course.