Open Source code which is widely used has a certain type of security. At ConceptPaper.org we call it Crowd Code Security. This is where an open source software is used widely across the world such that it is scrutinized a lot. A security hazard in the code would affect a large deployment base. Lots of people in the industry have access to the code and the development is also open. It is therefore greatly visible and checked. At ConceptPaper.org we call this Crown Code Security.
This goes hand in hand with another phenomenon. The negativity of self written or less deployed software. Even if a software is self written by an organisation (private or government) it could have a bug and would more likely have a bug. A self written software which is less deployed is more likely to have an unknown bug which is undiscovered and could be exploited. Talented engineers and hackers could discover the bug and use it before it is known or patched by the organisation writing the software. A self written software or less deployed software does not have crowd security as compared to a globally deployed software which has crowd security.