If you’re a Microsoft user and at all concerned about the security of your computers, you need to read this BoingBoing story about Microsoft’s cooperation with numerous 3-letter government agencies. If ever there were an argument for open source, here it is.
I love my Apple systems and I haven’t seen much about Apple doing this sort of thing but it does give me pause. If nothing else, it makes sense to use third party (open source) applications for full disk encryption and other security measures. It’s pretty clear that it’s foolish to trust any vendor large enough to be worth the government’s attention. If this sort of thing worries you too, check out Prism Break for some alternatives.