Using a Creative Commons license means anyone can take this content and republish it on the web.
Will our usernames be also republished? (I guess the answer is yes!)
What's to stop someone from creating stackoverflow2.com?
Actually, it's not clear what the ambit of the creative commons licence badge displayed on this site is. I cannot find any page that defines the terms between the users and Stackoverflow LLC.
Given that lack of clarity over what the intended ambit of the licence is, if push comes to shove, you are at the mercy of the traditions of whichever jurisdiction you litigate in.
Obviously, this isn't in any sense legal advice to anyone, just my observation and impression. Don't rely on this for any reason or purpose.
OP asked an interesing question! Those CC stuff is not clear at all. I added SOFAQ tag to the question. IMO we need to clarify this and add to the FAQ
See this recent post from Jeff
https://blog.stackoverflow.com/2009/06/attribution-required/
The requirements are:
So let me clarify what we mean by attribution. If you republish Stack Overflow content, we require that you:
Visually indicate that the content is from Stack Overflow in some way. It doesn’t have to be obnoxious; a discreet text blurb is fine.
Hyperlink to the original question on stackoverflow.com
Show the author names for every question and answer
Hyperlink each author name back to their user profile page on stackoverflow.com
So yes you can re-publish provided you meet those criteria
There's a cc-wiki image at the bottom right of each page. If you click it, you will see the terms of the license: StackOverflow's cc license.
Yes, you must be credited, but you can also demand that anyone using your content under the licence remove your attribution (see para 4(a) of the legal code)
What's stopping anyone from ripping off StackOverflow2 and create StackOverflow3?
The license only covers content, not the userbase. So if someone sets up SO2.com with all the content from this site, they still need to build a userbase and establish a community. Stackoverflow has the advantage that the names of Jeff and Joel are quite well known, so they had a userbase almost immediately simply because they were behind it, and I think that helped SO a lot.
It's all about the userbase.
How does this work with Wikipedia? My intuition is to say that this would be very similar.
It's true that the CC tag is rather misleading because it doesn't specify what exactly is licensed under CC license (well, by implication only).
Furthermore, I'm pretty sure such a blanked claim isn't legally binding. For one thing, national laws differ. For another, (I'm not a lawyer but I'm pretty sure that) the below tag doesn't give anyone rights to take the content users posted and reuse it under CC because the users aren't made aware of this. As a consequence, you can't just take away the copy- and ownership rights of the contents they posted.
/EDIT: To clarify: In order for this to work, users first have to agree to licensing their intellectual property.
Konrad makes a good point - I help to run a site which solicits content from users (http://www.geograph.org.uk) and we make sure each contribution is uploaded with a click-through agreement to a specific CC licence.
As there's no such thing on Stack Overflow that I recall, I'm also not convinced that I have licensed my postings under the CC licence.