I wondered a bit about that comment too. It's something of a tangent, but that the OS would load custom WDEFs (window definitions), CDEFs (control definitions),

I wondered a bit about that comment too. It's something of a tangent, but that the OS would load custom WDEFs (window definitions), CDEFs (control definitions), etc., and these had executable code in them, well that was how Mac got viruses. And there was a kind of hierarchy as I recall — where you could install a custom WDEF/CDEF/MDEF at the System level and it would be loaded/executed for all apps. With that line of reasoning though, as you're saying, it was not the resources themselves that were a problem but the way the OS naively loaded and ran them. Sandboxes were for kids. We definitely lived in a trusting time ... where the person computer really was for the one individual.