A couple weeks ago, Linus Torvald's dad revealed that the NSA had asked his son to build vulnerabilities into Linux, but his son had refused. The article then points out that it wouldn't have worked anyway, because Linux is open source.
Quick primer: Open Source means that not only is the program free, but so is the source code. That means you can take the code and make it your own and do whatever you want to it. A good example is Google Chrome; it's actually based on the Chromium Project. There's a whole operating system that's open source and it's called Linux. Every web page you visit is hosted on a computer that runs Linux. Linux was invented by a guy named Linus. His dad gave an interview (see above).
For me, the big revelation isn't that the NSA wanted to spy on something, because that's not really a revelation at this point. The big revelation is that open source software is so secure, ambiguously malevolent government agencies couldn't spy on it if they wanted to. That's not really a revelation; I've been arguing for years that open source software is more secure than closed source software. The US military agrees.
But this point is new. The Linux kernel has over 3700 individuals looking at it. How is anyone going to sneak in a backdoor without anyone noticing? (Of course, this also begs the question about closed source software like Microsoft Windows, who is answerable to no one.)
Meanwhile, my web development platform of choice is also open source. I'm talking, of course, about Ubuntu. Just one more reason why open source is the better choice.