I started that thread.
1. Please refer to https://bugzilla.wikimedia.org/show_bug.cgi?id=59146 "Enabling also edit access to Wikipedia via TOR" which much better allows tracking of this issue towards to find a practical solution.
2. Recommended reading:
Peter Wayner "Disappearing Cryptography" Third edition pages 225-227, 2009. ISBN 978-0-12-374479-1
Pages 225-227 Chapter 10.7.3 "Stopping Bad user":
"bad users of the onion routing network can ruin the reputation of other users. The _/*Wikipedia*/_, for instance, often blocks TOR exit nodes complete because some people have used the network to hide their identities while defacing the wiki's entries..."
In the further passages Peter Wayner explains a "one straight-forward solution is to use some form of certificates with a /_*blind signature*_/, a technique that borrows from some of the early solutions for building anonymous digital cash" (A typical example with "Alice" follows - must read this).