These are essentially 'super-technologies', much like government-requested back doors and master keys. It's not an overstatement to say that the potential they hold is on par with human genetic engineering - something the civilized world has thus far agreed is a road best avoided. Sure, the ethical dilemma of them is enough to give pause - but are the following not much greater risks?
* These systems will crowdsource "evidence", and by proxy, accountability - what happens when a mistake is made?
* Increased centralization will eventually enable 'single point of failure' scenarios in systems of a national/international scale.
* What happens when someone misuses or gains unauthorized access to such systems? Will the damage be reversible?
Such technologies will be deployed before accountability for them is defined, leading to a temporary absence thereof. Systems of the past (digital or otherwise) were inherently tolerant to misuse, malfunctions & misfires because only so much damage could be done before the errant behavior was discovered & handled. Today, how many seconds would it take to plunge a country into chaos?