"I believe it's entirely possible that most of the current "air shares" got there because MMs were responding to demand by shorting naked. "
Well, of course, that's exactly how they got there... BCIT was on the regsho list back then, if you recall. DCT is protecting these same brokers now.
You're missing my point. No MM who shorted naked before an official warning had been issued did anything wrong. Any MM who continued to short naked after DTC's announcement would, I think, be culpable. But we don't know when they stopped doing that. We just saw a lot of trading.
By the way, what happened to the certs that Sytner told Mario to "reprint"?