As I remember, you, benmaching, taught/told/showed Pol how to Fake GUID's.
Yes, I've admitted this, and I regret it. What's your point?
And I agree with Stof that once you know it
can be done, it's not hard to work out how (the thought had never occurred to me until Pol reported someone with an anomalous GUID connecting to s11, and I wondered how they got it). The fact that a GUID was stolen tells you nothing, therefore, about who did it.
Smokey, not only am I pretty sure that list is incomplete (Risujin knows how, vcxzet probably does) I'm also pretty sure your faith in clan members is misplaced. Yes, you may try to keep everyone in line and kick out malicious members, but some are always going to sneak in - the exact same applies to the tremulous community at large.
Caveman, I don't think read-only vars will ever stay read-only in an open-source game. The only way to evade problems like these is to make the authentication system non-transferable, so that what authenticates you to one server will not authenticate you to another. Tjw has provided exactly that so in time as this system is adopted, GUID theft will become much more difficult and security shall be restored. The only downside to this is that moving a server from one IP to another effectively makes the admin blocks in admin.dat useless. It's pretty much the only way to be sure, though.