The check is a positive one for presence. Items which aren't tagged are untrusted. If they throw out a signature they don't like, the system works perfectly fi

The check is a positive one for presence. Items which aren't tagged are untrusted. If they throw out a signature they don't like, the system works perfectly fine - it's treated like any other untrusted product. No one should trust a system that has a "don't trust this, it's bad" flag, it should always be "trust this, it's clean".