One of the advantages of open source, at least in theory, is that anyone can look through every single line of code in the OS to verify that there aren't any bugs that can lead to security problems. The idea that every part of the code is being examined by hundreds of programmers inspires a lot of confidence in a system, whether or not it is actually happening.

Do you think that Microsoft is at a fundamental disadvantage since it lacks this transparency?

In other words, does an open source model of development inspire more confidence in an Operating System compared to the model you use?

http://chris.pirillo.com/blog/_archives/2005/6/26/ 975606.html