Everything I write and submit here is copyright ME and I have provided bitcointalk exclusive license to its contents.
I'd like to see you DMCA: Google (cache), archive.today, archive.org, and countless other services.
It's the internet once it's posted it's out there for good, no going back.
He would be free to do the above, if he so wanted. A DMCA isn't a "fuck you I hate you go away", its a "remember that that is mine, and I am removing your access to it".
No we can't, most of the mirror sites continually update as they're clones. Only bitcointa.lk worked in the way you described, and that's been broken for 8+ months.