Beware! The virtual assistant might be demanding and could ask you to unlock the phone first but the Siri is far less resistant and will display contacts upon request
It seems like Apple is not getting its priorities straight and it might have realized that just now. The fingerprint scanner added to the iPhone 5s was a feature for added security but it seems like it can be quite vulnerable in front of Siri which can be a double agent here and is not so sure about its side either. Siri can very well bypass a security code or even a TouchID-secured screen on iOS 7.1.1 because for it this is as easy as asking politely. So this means that the fingerprint scanner cannot entirely be tested. This trick might not be in favor of the phone’s security because it can allow one to browse all contacts stored on the phone and make a call out to any one of them.
Even when the phone is locked, you can easily ask Siri to display the contacts. This is where the virtual assistant can be demanding and will ask you to unlock the phone to see the contacts but the Siri on the other hand is more flexible and less demanding at that. The video below shows how this trick actually works. And till Apple gets around to solving this issue, it would be wise to keep the siri switched off.