Well, at least until you realize that your image library has a security hole in it, or that your crypto library is so complex that it's not really possible to audit it in its current form.
And it was transmitted across the Internet, something which literally could not exist without free (in every sense of the word) software.
Irony is an important part of your diet, kids.
It certainly is, since the author of said article contributes heavily to freebsd. You know what else is an important part of your diet, kids? Reading and thinking before speaking.