Yes and someone specifically said they don't give permission above and the reply was basically "it's posted in public and I can do what I want with it".
Also the exemptions for archiving are for museums etc. Not just Joe public.
Also not a lawyer, but you can't just copy stuff and claim its for archiving and preservation. Theres exceptions specifically for museums and archives, not the public.
The specific thing for archive.org was an exemption to the dmca. Copyright one is for library's etc
And this is just the USA rules - it gets into a right mess when you factor in people post from all over the world.
But again, as it's clearly not clear... I dont care what's done with my content, I am glad it's being backed up. I just wouldn't claim I can do what I want with your content, which is we are now talking about this.
My way to approach the whole thing is back it up and post it. If someone wants to take it down, honour it.
Seems the sensible, fair and honourable way to handle the whole affair imo.