"We actually think our software is far more secure than open source software. It is more secure because we stand behind it, because we fix it, because you actually know who builds it. Nobody ever knows who builds a piece of open source software, where it comes from, who did it." - Steve Balmer, Microsoft.
The interesting part about this, checking the Microsoft Operating Systems and Programs security status on http://secunia.com/
shows that there are unpatched holes in almost all of their Products including the "Flagship" Windows XP, and Internet Explorer 6.
Yet if you check the status of Fedora 2 and 3, it shows that there are NO unpatched holes in either of the 2 products at the time of writting this. Even on previous occasions when I have checked the Fedora 2 and 3 status there have been no unpatched holes. It's showing that as soon as holes are found the are quickly patched while holes in M$ products go unpatched for a while.
I currently use Linux on 3 systems at home and hope to Migrate a 4th over soon once I can get all my programs and games running.