Writing in The New York Times, U.C.-Berkeley sociologist James B. Rule notes that most Americans seem untroubled by recent revelations about the NSA's domestic snooping. In a Pew Research Center poll, for example, 56 percent of respondents deemed it "acceptable" that "the National Security Agency has been getting secret court orders to track telephone call records of millions of Americans in an effort to investigate terrorism." Rule thinks they might reconsider if they contemplated the likelihood of mission creep:
Government planners have apparently invested billions of dollars to develop these new surveillance capabilities. Given the open-ended nature of this country's relentless campaign against terrorism and other declared evils, it would be naïve to imagine that the state's grip on "big data," achieved at such cost, would be allowed to atrophy in the foreseeable future. It is far more likely that new uses—and, inevitably, abuses—will be found for these surveillance techniques….
The promise that one especially egregious sort of crime (terrorism) can be predicted and stopped can tempt us to apply these capabilities to more familiar sorts of troublesome behavior.
Imagine that analysis of telecommunications data reliably identified failure to report taxable income. Who could object to exploiting this unobtrusive investigative tool, if the payoff were a vast fiscal windfall and the elimination of tax evasion? Or suppose we find telecommunications patterns that indicate the likelihood of child abuse or neglect. What lawmaker could resist demands to "do everything possible" to act on such intelligence—either to apprehend the guilty or forestall the crime.
In its story about the ACLU lawsuit challenging the NSA's mass collection of phone records, the Times notes there is precedent for using powers justified by the threat of terrorism to investigate more mundane forms of crime: "An expanded search warrant authority justified by the Sept. 11 attacks, for example, was used far more often in routine investigations like suspected drug, fraud and tax offenses." Have a look.
Mission creep seems especially likely in the case of phone records and other data held by third parties, which according to the Supreme Court can be perused by the government without raising any Fourth Amendment issues. That means such information, which includes cellphone geolocation data as well as sensitive material stored on remote servers, gets only as much privacy protection as Congress decides to give it. Notably, a majority of the Pew respondents (52 percent) said the government should not "monitor everyone's email and other online activities if officials say this might prevent future terrorist attacks." Presumably there would be even more opposition to such surveillance if the goal were fighting crime in general and if people understood how vulnerable their online privacy is under current law.