I don't think Plagiarism is something that needs to be pointed out as being something you can't do. First of all, this is something that people should know they shouldn't do, for a number of reasons, and I believe most people who do this know it is wrong, but do it anyway.
Well it shouldn't have to be but it really does need to be pointed out that this isn't acceptable and you can see that from the number of threads from people in Meta asking why they were banned and if they can get a second chance, so people should be made aware of the rules and the punishments for doing this so there's no excuses then.
I actually think there are a fairly small number of threads in meta disputing bans (due to plagiarism), especially when compared to when BadBear was banning people for 'low effort posts + paid signature' wholesale. I also have noticed that many of these threads are asking why they have been banned, and often someone will post evidence they were copy/past spamming, and I also note that I understand the ban message is something along the lines of "sorry hilariousetc you have been banned by a forum moderator" when they are permmabanned, and does not have a specific reason, so it is possibly these people don't know they were caught plagiarizing.
Also, I don't think it is as big of a problem in terms in the number of people getting into trouble doing this. Sure there are very many instances of this happening, however I suspect this is done by a fairly small number of people with a very large number of sockpuppet accounts, and I suspect this is often done via some kind of automation/AI.
Sadly I think you're very wrong. Copy and pasting and plagiarism is a huge problem and I'd say this sort of abuse is actually becoming endemic and almost commonplace now. Probably 50+ users a day are being banned for it and many multiples more will be getting away with it.
I don't dispute this is a problem in the forum, I am totally in agreement this is a major issue that needs to be addressed. I have previously advocated the administration scrub posts for copy/paste posts posted, and to scrub posts of a plagiarism database.
I do not dispute that 50+
accounts are banned for this every day, however this is accounts and not necessarily
people. We certainly do not see 50+ threads of people questioning why they are banned, substantially lower than that. Also, refer back to when BadBear was banning sig spammers wholesale, there were periods of time when there were many threads opened every day by
people banned. This is also a fairly new problem, and it went from absolutely not a problem to being an epidemic almost overnight.
I have also noticed that many people caught copy/past spamming are low rank accounts, which means people are not earning very much from these copy/paste spamming. Many accounts have been caught copy/paste spamming as newbies, which previously could earn very little from paid signatures.
I suspect that many of the copy/paste spammers are probably people we don't really want here regardless of their copy/past spamming. I suspect they are either bump spammers, are engaging in some kind of 'black hat' SEO (either positive, or negative -- I am not sure), or are otherwise trying to create a false sense of interest in projects.