they will check the "date" , very easy to determine who posted first.
Yeah, It's easier to determine who posted first but if someone instead just decides to edit his older blog or site, it wouldn't be easy, would it?
Yes. This actually already happened once. Someone got framed for plagirism and theymos found out, so he reversed the ban. Ill tru to find the post and link it here for you.
Okay, that's good to know if the ban can be reviewed in such circumstances
Click right>>>check the source code, can tell you a few things, especially with WordPress. Google cache and archive.org too.
And if someone edit a 20 years old blog post to replace it with a bitcoin-related content, it"s easy to guess something is wrong, or the guy travelled in the future, got a Nostradamus illumination, ...