The Dark Night (2008), the latest Batman picture is full of moral challenges. One of them is the mobile-phone-powered surveillance state.

Wayne Enterprises backdoors mobile phone hardware throughout Gotham City, enabling continuous audio surveillance and location reporting. A WE computer system filters all the streams, matching against samples of Joker's voice. This is all for Batman, not for the corrupted Gotham Police Department. 

Lucius Fox, CEO of WE, tells Bruce Wayne this is too much power for one man. Wayne agrees and destroys the system after one of the Joker's arrests.

Before we leap from fiction to reality:

• Does the potential exist for turning-on mobile phones without the owner's consent? Turning citizens into open microphones?

• With enough money, could you build the filters to match voices or listen for words/phrases in near real time?

And then the design constraints...

• What pressures could be brought to bear upon the operators of such a system?

• What systemic resistance could you build into a system so it is not abused? so it is not abusable?

• Could you architect the mobile network to prevent the construction and operation of such a system?

In our real world,

• police complain Skype is too encrypted for on-the-fly wire taps,

• Google is creating a new mobile phone operating system,

• Nokia is community-sourcing Symbian,

• Apple is buying its own semiconductor fabrication factories, and

• US phone companies break faith with customers, giving private customer data to spy agencies without FISA court compulsion.

If industry has the power to both enable private surveillance and prevent it, where do its obligations lay? As citizens, what is our responsibility?