"For most people, the word 'open' might seem rather benign,
conjuring only images of open fields or perhaps a late night eatery
still catering to hungry travelers. For military personnel,
however, 'open' has a negative connotation. Any good soldier should
bristle at the word. Things that are open need to be secured, for
they are vulnerabilities where an enemy force could encamp.
"This latent fear of the word 'open' is as good of an
explanation as any we've heard on why the military has thus far
been reluctant to adopt open source software. The word certainly
does not inspire the same degree of trust as other words, such as
'Raytheon' for instance..."