Seeding is opt-out, not opt-in… but it is usually a default that has to actively manually overridden. Most users never touch those settings. The average pirate downloading a torrent is seeding whether they know it or not.
The protocol absolutely does not enforce seeding. A client can lie to the tracker, cap upload to 0k. BitTorrent has no mechanism to compel one to share. Leeching a file, downloading and sharing no forward packets is possible. While the "social contract" of seeding is entirely a norm enforced by private trackers and community shame. It is not the protocol itself.
you're uploading before seeding, and i'm willing to bet Meta weren't seeding but, as they correctly stated in that regard, they're sharing even when they try their best not to because of the way the protocol works as zero-upload is typically impractical for any significant size files
some trackers will additionally penalise you for not sharing file parts, but this depends on the tracker
The original design called for some kind of tit-for-tat algorithm, but it's long obsolete and you get whatever bandwidth the seeder has.
Most people that speak of leeching or not seeding really are talking about not seeding at all after they've completed. In fact, most clients will let you set upload speeds to a trickle but not zero (zero means unlimited in most clients). From a legal standpoint, that already means you uploaded.
I’m not aware of any clients that will refuse to share data with clients that are configured to not upload. I don’t even see how they could determine that, especially in situations where there are no other peers to upload to, and given that stats are entirely self-reported and clients that send bogus numbers exist.
You would need a central tracker that cares, which is what private torrent communities rely on, but not public/DHT torrents such as those discussed here.
You will probably get the data eventually, and it really depends on the composition and configuration of the swarm, but generally, you do need to upload if you want to ensure the fastest and most reliable download.
The case for doing this would be just so you can have this ridiculous legal defence Meta seem to be trying to pull out. Really no other good reason. Even for the most parasitic leeches, zero upload is a bad strategy.
You totally CAN disable all uploads in the torrent protocol. Just set the "upload budget" to zero in most clients. Just nobody realizes they can do that.
Bittorrent is wildly successful in part because every popular client makes it nontrivial to "opt out" of it's more socialist components (chunk trading, DHT participation, seeding by default).
Making an "leech behavior only" torrent client is straightforward and viable.
going 1 by 1 would be quite the exercise in itself considering just how much variety of formats, styles, crap added in the files, random password crapware, etc etc you find for anything other than the most trendy stuff
No, because those cases were pirating-while-poor. This is pirating-while-trillion-dollar-corporation, which falls under a completely different section of the law.
It is interesting to follow how this plays out for Meta and how that will impact future cases.
In the UK you can only claim for the actual damages incurred, which at most will be the profit you would've made on the sale of that book. Which makes most claims for private infringement uneconomical for corporations.
(2) The court may in an action for infringement of copyright having regard to all the circumstances, and in particular to—
(a)the flagrancy of the infringement, and
(b)any benefit accruing to the defendant by reason of the infringement, award such additional damages as the justice of the case may require.
If it's fair use, no licensing fee is needed.