Sorry. "Identification, Friend or Foe" - i.e. knowing who not to attack.
> Oh, and it doesn't matter if they are wasting energy
> attacking each other,
> as only ones surrounded by other grey goo would be spending
> more energy
> dissassembling each other, the ones on the edge would be
> happily digesting
> more non-grey-goo. It doesn't matter if the ones in the
> middle 'die' as
> they aren't within attacking range anyway..
Even if you don't buy mark's objections, this is a fatal problem the instant you run into defensive nanobots. The frenzied goo is simply a thin shell, while the smart defenders have a rear area where they can muster reserves, mass-produce new units, and so forth. An organized force will defeat a frenzied mob easily.
Another problem is energy supply. The gray goo is limited to organic matter and solar power for energy supply, so its growth rate can't be too much faster than ordinary microorganisms. A defensive system can mass-produce nanobots in industrial fabricators running off the electrical power grid. Thus, the defensive system can have a far higher reproduction rate.
Billy Brown, MCSE+I