I was once at a conference where a delegate proudly informed me that the great benefit his company had was that he was running Linux servers and not IIS which, according to him, meant no security worries. I just hoped that no hackers were listening to him, because that sort of lazy and ignorant attitude to security will lead you into problems sooner or later.
And I read with interest that www.zone-h.org, a site dedicated to monitoring attacks on all systems, reports that Linux servers account for no less than 93% of all verified attacks. Sobering news indeed for my delegate friend.
It's worth checking out www.zone-h.org, because it makes interesting reading.