What? Open source in a cloud service stack means that if the NSA thugs show up and order you to insert intercepts into your software on pain of being "disappeared", it's far EASIER to change the source and recompile than it is with proprietary software.

rimantas is referring to using open source in a cloud service, not authoring and distributing it.

What are you talking about? Open-source doesn't protect against backdoors even theoretically. Think about it. Have you read every line of every piece of software you run? Would you understand it all if you did? Even if you read the source code, did you actually compile it all from scratch or did you use a binary (like virtually every single OSS user on earth)? Are you certain that the compiler you used wasn't compromised? How exactly?