When you are the dns root record and in many cases hosting too for some 60-70 million domains, someone in the internet is wanting to attack someone at godaddy all the time. There isn't a time they aren't being attacked somehow in all reality, and I'd presume it's much the same for Linode.
The means of really combating a ddos is costly and extensive, this is why most use a service like prolexic or silverline, and typically with some massive infrastructures that comes with it. Anything less than n-by 40gb disposable internet pipes, preferably regional as you are, you can/will be smited at will.
They'll exploit user queries any way they feel they can, same as google or facebook. Apple is simply trying to take hold of a "voice search" market the same way google dominates the "web search" market. Currently apple uses google for the backend search, but once they swing their entire ecosystem to using it, apple can offer up their users' queries to the highest bidder, such as bing instead of google, and use for their their own marketing/data mining. Balmer might monkey-dance for apple to make themselves relevant in search again at the opportunity/cost, even as a apple's sub.
The means of really combating a ddos is costly and extensive, this is why most use a service like prolexic or silverline, and typically with some massive infrastructures that comes with it. Anything less than n-by 40gb disposable internet pipes, preferably regional as you are, you can/will be smited at will.