The "sensible" solution for plagiarism would be this.
a button on every post labeled with" Click me NOW" , takes you to another page where you need to quote the original text, the two texts along with the timestamp run in simple query that checks the integrity of the report by matching the two texts, if it matches , BINGO ! that account gets INSTANT BAN for a limited period of time which equals to his lifetime.
and yes , the button should be available to everybody including newbies so that they can ban higher rank members who copy and paste.
I can tell you this is going to be a 100% plagiarism free forum, as everybody will be watching over everybody else.
and this to me is the ONLY "Sensible" punishment for somebody who steals the words of others and present them as their own.
That's not a good idear at all... For example, if i had some kind of grudge against somebody, I could just copy one of their original posts and paste it on my blog with a backdated timestamp, so it looks my blog article is older than the original post my victim made... Then i could just click the button => BAM autoban.
I could even up my stealth so i wouldn't face any punishment if somebody found out the victim was autobanned due to my scammy methods... I could simply register a free .tk domain, then create an account on a free webhost and create a blog there (all over a VPN or tor)... Then copy somebody else's work and post it on my blog with a backdated timestamp... Then i could create a newbie account on bitcointalk over my VPN or tor, and get a senior member autobanned... Sure, maybe the ban wouldn't stick, but the member would still lose access to his/her account for a while untill the admin has time to look at his ban appeal and unban his account.
I'm not in favor of an automatic ban mechanism...
For the rest of this thread: i'm not a political person... I , personally, wouldn't like to see somebody getting severely punished because he or she copied my work, but i completely understand if other members do have severe problems if their work gets copied... It's against the law to plagiarise in many places around the globe, so i completely understand Theymos has to make a point here, it probably would reflect poorly on him if he let people plagiarise without punishment.
I wouldn't be opposed to the fact of unbanning somebody if the violation happened a long time ago, and if the member has behaved in a suitable manner for a long, long while. In the law of my country, there's something called a "verjaringstermijn". It basically means that if you commit a crime, you can only be punished for this crime the next x years after the crime. The amount of time needed for a crime to become "unpunishable" depends on the type of crime.
I don't know if there's something similar in the US (afaik, that's where the bitcointalk server is hosted), but i can imagine a member who joined in 2010 and commited the crime of plagiarism once in the first year he's a member but never commited the crime again in the next 8 years (while still remaining an active member) could potentially fall into a different category than a shitposter.