free software security - clarifying a misperception

I've heard this confusion regarding free software security several times...

"We need proprietary software to control our computers. Free software means 'anyone' is 'free to change' it, so it's insecure."

When you have a free software program, you are free to change your copy. Nobody else can change your copy as you are the one who controls that copy. If another gets a copy then they may change that copy. But that does not affect your copy. Some have associated the "freedom to tinker" with the assumption that control over your own data and software is negated. This is false.

By contrast, if you use proprietary software and have not signed an associated NDA or obtained an unauthorized copy of associated source code, you are automatically handicapped in regard to system security. This opens the possibility of proprietor (or NDA-related and/or pirated) corruption. If you're a programmer, free software can place the decision to trust in your own hands. And if you're only a user, trust is placed in a whole world of programmers incapable of hiding malicious intent (e.g. spyware) from one another due to the very nature of free software itself. This very nature means that given roughly equal maturation time, a free software system has a perpetual security edge over a proprietary system.