Comment by sigmoid10

This. Closed source doesn't stop people from finding exploits in the same way that open source doesn't magically make people find them. The Windows kernel is proprietary and closed source, but people constantly find exploits in it anyways. What matters is that there is a large audience that cares about auditing. OTOH if Microsoft really wanted to sneak in a super hard to detect spyware exploit, they probably could - but so could the Linux kernel devs. Some exploits have been openly sitting in the Linux kernel for more than a decade despite everyone being able to audit it in theory. Who's to say they weren't planted by some three letter agency who coerced a developer. Relying on either approach is pointless anyways. IT security is not a single means to all ends. It's a constant struggle between safety and usability at every single level from raw silicon all the way to user-land.