On sites in the Stack Exchange network, the core of the Terms of Service is this statement:
"You agree that all Subscriber Content that You contribute to the Network is perpetually and irrevocably licensed to Stack Exchange under the Creative Commons Attribution Share Alike license."
From my point of view as a Stack Exchange user this is very nice, because (as I interpret it; IANAL) it means I actually own my own content, but just license it out to Stack Exchange. It's also very nice for this site, because it means we can legally import questions from SE sites without needing permission.
There's a couple of issues relating to this that I'd like to open for discussion:
1. For posts imported from SE sites, there has to be a notice along the lines of "this user contribution licensed under cc by-sa 3.0 with attribution required" (with a link to the license), otherwise you're violating the terms of the license. (You will find a notice along these lines at the bottom of every Stack Exchange page.)
2. Does Physics Overflow have a similar policy? I.e. are all Physics Overflow posts owned by the user and licensed to PO under a CC license? I've always thought this was a rather enlightened policy of Stack Exchange and I'd be very happy if PO went the same route. If that's how it's meant to work here it would be good to have a ToS that makes it clear. (And conversely, if that's not how it is here, it would be nice to have a clear "all your posts belong to us" type of ToS, just so we know.)