What is a program you "trust"? Something you bought online from a curated app store? Those occasionally have trojans as well. Something you downloaded? Well, if it's open source, that's the norm. Something you build from source? Most people wouldn't be able to spot an exploit hidden in the source code.
So.. it's run everything sandboxed by default the recommendation for regular users? Or is it "do not download or buy anything, it's simply not safe"?