What did you expect?
Apple, Google, Microsoft etc will do anything they can to hold onto any data you give them, and they'll have their excuses as to why they need that data, be it genuine or not. Haven't people learned by now that this is the norm these days. Quite frankly, if you're worried that someone's gonna find out about a boil on your bollock, then perhaps siri isn't the best thing to be asking about it.
Personally, I've already learnt that they will grab all sorts of data out of my phone unless I go very much out of my way to disable such things, but then that makes a few apps and functions not work.
So what if they know where I am, or what I've asked siri, or even what I've photographed. It's been known that they can do these things, and people need to wise up to this, and either accept it, or go back to your nokia 8210.