One part of the conversation is completely *facepalm*/smh (shaking my head) worthy, though. Someone brought up the extremely ludicrous notion that Linux would have protected the Iranians against Stuxnet and Flame. Linux totally would not have given the Iranians any extra protection.
The Stuxnet attacks are highly sophisticated and targeted and were able to get through every layer of the Iranian infrastructure to get embedded within the centrifuge controls. Flame, at least as far as I can tell, may have been used to provide the reconnaissance needed in order to build Stuxnet. It wouldn't have mattered what types of computers and OSes the Iranians used. The attackers would have just found vulnerabilities in any of them and developed exploits accordingly.
These hacks were very difficult to defend against and would have required a very thorough "defense in depth" strategy with a dedicated staff of security analysts to monitor and analyze network, OS and application logs and health. Even then, given the fact that spies were involved, It would have been an uphill battle to stop these attacks from succeeding.
There are certainly advantages that Linux gives to organizations within datacenters. Protecting them against highly advanced and targeted threats that exploit unknown weaknesses is not one of them, in my opinion.