Process safety and stuxnet worm?

Of late a number of articles are appearing on impact of stuxnet worm on process safety and it is an eye opener for me. Though, I am bothered about safety of my computer at home and office, it never occurred to me that this can lead to accidents in plants which are operated from computers. Possibly, this is due to the fact that only limited sections are operated from computers in the facilities which I saw all along.
Now that I am aware of this stuxnet worm and its cousins that can affect process safety, I though what we can do to prevent such process safety hazards and following are some that came to my mind.
1. As the worm has to enter through internet / removable disks, these computers should not be connected to internet.
2. There should not be any provision to use pen drives, floppy drives, CDs.
3. Realtime protection from viruses, worms, etc should be available. For this realtime protection program loading, the server system should be under lock and key control of a senior officer. If it is affected, then this man only is the channel for viruses/worms to enter the system.
4. A realtime standby system operating on a different mode should be available (diversity in redundancy).
5. Backup should be taken in every shift.
6. The persons manning the control room should change their dress totally in the change room and enter with company provided dress before entering control room / server room.
7. Control room, server room, etc should be under surveillance.
8. As it is seen in the movie Die Hard (2?) of taking over all control systems by connecting from distance, the cables connecting servers with plant data monitoring and control cables should be secured and any attempt to interfere should be sensed and alarmed.
9. Like railway gangmen check the rail tracks regularly, cable system should be checked physically also by authorized staff.

Above are some thoughts which came to me for ensuring process safety from worms like stuxnet. I have to understand about how plants are operated from computers and what are their defence systems.

Empowering safety department - How long?

Recently, I read an article that the new boss of BP is reshuffling the safety division and is making it as the most powerful voice and that they can intervene in any of the technical functions of the BP. This is what is required by law also. Only that we do not follow.
I do not doubt about the capabilities of earlier safety staff of BP. I doubt only about the production staff. It is normal to see in any production facility that production staff and their bosses pay little attention to what safety department says. As the safety department is part of the facility, it can only advise. Implementation depends on the whims and fancies of the production department. Safety department becomes powerful only when the top man gives unconditional support to it. In the present case also, though the new boss ALLOWED safety division to be powerful, the time upto which it can be allowed to function this way will be limited, as Mr Trevor Kletz said, "corporate memory is short". As the memory fades gradually, well meant safety advises become additional work and time consuming for the production staff and slowly they start ignoring the safety advises. By that time, the BP boss who is making safety division powerful may also leave the organization and the STORY WILL REPEAT. Again as observed by Mr Kletz in his books.
It is my observation which evolved with my interaction with many of my friends in various industries and also from my knowledge of reading various books, safety blogs and investigation reports of CSB, HSE, etc that it is a worldwide phenomenon of giving importance to safety only after an accident and then slowly forgetting about it.
A KNEE JERK REACTION INDEED.