Copy Should

We've discussed the CopyRight issues as they relate to Wiki, but what about the CopyShoulds?

How serious of a breech of etiquette is it to copy someone's post from forum such as the XpMailingList, UseNet, or SlashDot, without specific permission?

Reasons why you Should:

It keeps the precious ideas alive. The WikiWikiWeb is where information goes when it has reached puberty. Those that couldn't make it just die quietly in their native forums.
It's a quick way to revive a conversation. If it is an older post, maybe some relevant factors have changed. Even if it isn't old, the Wiki has a different mix of people, and might bring a fresh view.
"It's easier to ask forgiveness than to ask permission."
Why not? What's the difference between one public forum and another?

Reasons why you Shouldn't:

The author hand-crafted the post to have maximal meaning for that specific audience. You don't want to destroy these subtle interactions, do you?
The author might not believe that it's proper etiquette. This should be respected even if you disagree.
It might breach the legal CopyRight, depending on the forum.

Therefore:

: If you can muster the patience, write the author and ask them permission. It gets all of the good points above and none of the bad. Plus, they'll enjoy the compliment.

Alternate solution:

: Paraphrase. This allows you to re-tailor those "subtle interactions" to the new forum, possibly removing the irrelevant portions. (But this solution is still potentially rude and potentially illegal.)

The acceptance of the ideas, concepts and expressions and the adoption of the same are important reasons for CopyShould. Since ImitationIsTheSincerestFormOfFlattery?, and for an idea to live, it must replicate and generate relatives, such copying should be encouraged. That assumes that ideas are so important that they should not be owned in a manner that restricts or prohibits the idea's existence or extension.