Yesterday I started a thread on new wiretapping technologies, and their policy implications. Today I want to talk about how we should deal with the ability of governments to record and store huge numbers of intercepted messages.
In the old days, before there were huge, cheap digital storage devices, government would record an intercepted message only if it was likely to listen to that message eventually. Human analysts’ time was scarce, but recording media were relatively scarce too. The cost of storage tended to limit the amount of recording.
Before too much longer, Moore’s Law will enable government to record every email and phone call it knows about, and to keep the recordings forever. The cost of storage will no longer be a factor. Indeed, if storage is free but analysts’ time is costly, then the cost-minimizing strategy is to record everything and sort it out later, rather than spending analyst time figuring out what to record. Cost is minimized by doing lots of recording.
Of course the government’s cost is not the only criterion that wiretap policy should consider. We also need to consider the effect on citizens.
Any nontrivial wiretap policy will sometimes eavesdrop on innocent citizens. Indeed, there is a plausible argument that a well-designed wiretap policy will mostly eavesdrop on innocent citizens. If we knew in advance, with certainty, that a particular communication would be part of a terrorist plot, then of course we would let government listen to that communication. But such certainty only exists in hypotheticals. In practice, the best we can hope for is that, based on the best available information, there is some known probability that the message will be part of a terrorist plot. If that probability is just barely less than 100%, we’ll be comfortable allowing eavesdropping on that message. If the probability is infinitesimal, we won’t allow eavesdropping. Somewhere in the middle there is a threshold probability, just high enough that we’re willing to allow eavesdropping. We’ll make the decision by weighing the potential benefit of hearing the bad guys’ conversations, against the costs and harms imposed by wiretapping, in light of the probability that we’ll overhear real bad guys. The key point here is that even the best wiretap policy will sometimes listen in on innocent people.
(For now, I’m assuming that “we” have access to the best possible information, so that “we” can make these decisions. In practice the relevant information may be closely held (perhaps with good reason) and it matters greatly who does the deciding. I know these issues are important. But please humor me and let me set them aside for a bit longer.)
The drawbacks of wiretapping come in several flavors:
(1) Cost: Wiretapping costs money.
(2) Mission Creep: The scope of wiretapping programs (arguably) tends to increase over time, so today’s reasonable, well-balanced program will lead to tomorrow’s overreach.
(3) Abuse: Wiretaps can be (and have been) misused, by improperly spying on innocent people such as political opponents of the wiretappers, and by misusing information gleaned from wiretaps.
(4) Privacy Threat: Ordinary citizens will feel less comfortable and will feel compelled to speak more cautiously, due to the knowledge that wiretappers might be listening.
Cheap, high capacity storage reduces the first drawback (cost) but increases all the others. The risk of abuse seems particularly serious. If government stores everything from now on, corrupt government officials, especially a few years down the road, will have tremendous power to peer into the lives of people they don’t like.
This risk is reason enough to insist that recording be limited, and that there be procedural safeguards against overzealous recording. What limits and safeguards are appropriate? That’s the topic of my next post.