Currently our default license for EN wiki is CC BY-SA 3.0, but isn't this a bit odd for IP editors and vanished users? Wouldn't it make more sense if IP editors were licensing their edits as CC SA, and vanishing users as part of vanishing were relicensing their edits as CC-SA?
In one case the only attribution we can make is to an IP address, in the other the editor doesn't want to be attributed.
Changing the default license would then give a more transparent reason for registering an address. If you would like your edits to be attributed directly to yourself or indirectly via a nom de plume, then create an account and your logged in edits will be licensed *CC BY-SA 3.0.*
Regards
WSC