Actually, I'd beg to differ.
A lot of talk goes the "Security by obscurity" route. I.e. Don't release source, don't let anyone know what you're doing.
Part of the job I do involves system security, and if there's one thing that's apparent, security through obscurity doesn't work.
If you close your source, and don't let anyone know what's inside it, then you will almost definately miss something (if the app is sufficiently sizable).
And there will be someone out there able to crack it.
However, a good code review by a grouip of experienced and good coders will bring a good many of these to light. And in the end, they have almost as much to lose as you do.
By giving advice, they're actually laying part of their reputation on the line, and reputation is pretty important to the open source community in general (well, far as I know so far.. :) )..
Anyhow, the anonymous troll like monk that posted before this kinda killed his own argument.
"Take nobody's advice but your own" is advice, which he's suggesting you don't take, so, should be ignored.
Advice is a good thing, as long as you remember it's just that. Advice. What you do with it is up to you..
My personal thoughts on things are "Get the bugs found before programs hit production level where someone else will..". Code reviews are the best way I know to do that..

Just my tuppence worth,

Malk