Nanite Limits

Nanotechnology is an astoundingly powerful tool that, with the right programming and forethought, can make miracles a reality where otherwise it would be impossible, extremely expensive, or just impractically long to do. They are not without limitations, however. At the heart, they are little machines. They have extremely limited(essentially none) intelligence, individually. They rely on an off site computer to coordinate their efforts with limited cooperative power with local transponding nanites that relay commands and report changing environments.

Weaknesses

The transponder nanites are the weakest point of the nanite chain of command. A sharp burst of EMP interference will cause them to lose connection with the off site computer, or even cause damage to their internal radios. If enough of them are brought offline, the entire nanite mass becomes inert until new transponders can be assembled.