No one has a legal right to "edit" on the Wikimedia servers.
But *everyone* has a moral AND legal right to edit any article they like and post it, print it, sell it, etc. -- wherever they want, other than at Wikimedia -- without any limit. This is called the "right to fork". It's an essential aspect of the GFDL.
I'm not anal (I mean, IANAL), but I know this much...
Ed Poor