It is FUD since it is not impossible to make these changes, it's just (intentionally) more difficult than casually supplying a sudo password. Anyone can detect

It is FUD since it is not impossible to make these changes, it's just (intentionally) more difficult than casually supplying a sudo password. Anyone can detect signature changes in a system directory and anyone can boot to a recovery volume (either the default Apple one or one provided by an anti-virus company, if desired) to make whatever corrective change they want.