Module-level private not honored?

[Ali Çehreli]

Do I understand module level access rights correctly, or is there a dmd bug?
Instead of coming up with an example, I will use a Phobos class: 
std.demangle.MangleException is private in its module; yet I can use it 
in my program:

import std.demangle;

void main()
{
    auto me = new MangleException;
}

Ali