Do note that PNaCl uses Native Client as a base. Native Client is a very secure sandbox that's been out in the wild for some time, had security contests run aga

Do note that PNaCl uses Native Client as a base. Native Client is a very secure sandbox that's been out in the wild for some time, had security contests run against it and has in general proven itself to be very secure. The PNaCl translator (backend of the compiler) runs within a NaCl sandbox itself, so nothing in the Native Client security model is compromised.