Lets say we have WebSite(A), and at the bottom of their website they
have: "your submission becomes the intellectual property of the owner
of this domain name"

I own WebSite(B).  If someone, not myself (a user of my website),
submits something that can be found on WebSite(A).

1. Can I be held responcable for this information?
2. What if it's not an exact copy; can I be held responcable?
(Example: "George W. Bush was once trapped in a paperbag for 3 days"
-> ".... stuck in a paperbag for 8 days")
3. If UserA submitted "Blah Blah Blah" to WebSite(A), can UserA submit
"Blah Blah Blah" to my website, WebSite(B)

Any additional information would be greatly appriciated!

The user of your website has violated your copyright on the material.
They can be held responsible for that. And, naturally, if you did not
submit the work to website A, you cannot be held to the terms. In
fact, webnsite A must remove your material right away, since it
violates your copyright.

I would write to website A, explaining that the user violated your
copyright and that therefore website A is now (inadvertantly)
violating it, too. Let them know the material should be removed within
seven days.

Good luck,
Kriswrite

IANAL, but I have serious doubts about the enforcability of that
clause at the bottom of the page.