Is plagiarism always intentional or can there be some specific cases in which it is not? It is not clear to me.
Possibly.
- It's why plagiarism report will be handled case-by-case and very careful by moderators.
- Moderators won't carelessly use their ban hammers immediately after they receive a plagiarism report. They will look at proof of plagiarism and post history.
- It will be handled by moderators and escalate to global moderators or admins. With the complicated escalation process, I don't think reports will be handled inaccurately.
Plagiarism is what gets people permabanned, not just copying. Plagiarism is copying with the intent of passing the work off as your own. In essentially all cases, plagiarism deserves a permaban because it usually proves definitively that the person is here for the wrong reasons: to fill up space in order to get paid, not to actually discuss or contribute. If someone was able to convince us that they were plagiarizing just to eg. impress people rather than to fill up space, then a lesser ban of a few months might instead be warranted. But this has never happened AFAICR. (Arguments based on plausible deniability aren't going to work; we don't need to prove that you had the motive we see in your actions.)
Posts are reported to moderators who check out the report. If the poster needs to be banned, the moderator sends a ban report up to a global mod or admin. The global mod or admin handles all of the ban reports they get at around the same time. Either the admins or global mods don't need to check every account because they trust the moderators to have already done so, or they check quickly because every such report contains references and links to the plagiarism post and to the source text so checking takes little time.