Personally, I have never been a fan of online VCS. The human aspect of public vs private aside, it has always just seemed less secure to me.
But it's the wave of the future, security be darned.
Probably, not sure that's always the case, but certainly for anything that might be an issue if released, I'd be wary of an online VCS.
However I'd argue that the vast majority of all code I've ever seen written isn't an issue from a disclosure of intellect area. Most of our code really isn't doing something that makes our business succeed or fail. It's the execution of business itself, not the software that matters.
I do think, however that potential holes in security, based on poor coding or coding mistakes, is an issue.