I wish it was a contrived problem. However, this is the conceit by which the edits are attributed for licensing purposes, and it's a non-trivial matter. While I'm fully supportive of finding another way to do this, it is a fundamental issue that would require fairly extensive legal consultation to change, given that we've been using "IP address as assigned to a specific individual" as the licensee for...what, almost 14 years?
We know that Tor exit nodes are (by definition) not IP addresses assigned to the contributor, and there is no reasonable prospect of tracing back to the original IP address (unlike many other anonymising proxies). Thus the attribution issue.
Realistically there is no reasonable prospect of tracing back an individual IP to a real person 80% of the time without a court order, which is extremely unlikely to ever happen. Even then you can only really link the IP to who's paying the bill, which is only weakly circumstantially related to who really "owns" the edit.
If we're going to consider the theoretical possibility that we can might be able to link back an IP to a person with certainly, we might as well start considering that we might be able to do the same if we get everyone in the tor circuit to collude...
--bawolff