Do past abuses of personal data point toward future abuses of NSA metadata collection?

Stephen Walt spotlights why we worry about metadata collection:

The real risk to our democracy is what this situation does to potential dissenters, whistle-blowers, investigative journalists, and anyone else who thinks that some aspect of government policy might be boneheaded, unethical, or maybe even illegal. If you are one of those people -- even on just a single issue -- and you decide to go public with your concerns, there's a possibility that someone who doesn't like what you are doing will decide to see what they can find out about you. It doesn't have to be the attorney general either; it might just be some anonymous midlevel bureaucrat or overly zealous defense contractor. Or maybe it will be someone who wants to suck up to their superiors by taking down a critic or who wants to have their own 15 minutes of fame. It really doesn't matter: Unless you've lived an absolutely pristine online and cellular life, you might wake up to discover that some regrettable moment from your past is suddenly being plastered all over the blogosphere or discussed in the New York Times. 

 In a way, though, Walt's evidence that we should worry cuts two ways:

Does this danger sound far-fetched? Recall that when former diplomat Joseph Wilson published an op-ed debunking the Bush administration's claim that Saddam Hussein was trying to score uranium from Niger, some government officials decided to punish him by blowing his wife's cover as a CIA agent and destroying her career. Remember that David Petraeus lost his job as CIA director because a low-level FBI agent began investigating his biographer on an unrelated matter and stumbled across their emails. Recall further that long before the Internet age, J. Edgar Hoover helped keep himself in power at the FBI by amassing vast files of dirt on public figures. Given all that and more, is there any reason to believe that this vast trove of data won't eventually be abused for political purposes?

An obvious response is that none of these abuses entailed metadata collection of the sort that the NSA engages in. On the other hand, Dick Cheney worked his own bypasses of intelligence services' analyses and reporting of "human intelligence," getting raw, un-assessed informants' claims that supported his favored conclusions delivered directly to him through parallel channels that he created.  Could he have done the same with metadata? Could a latter-day Cheney bypass minimization controls and the FISA court to obtain information on a specific American with no manifest ties to terrorist groups  -- and either effectively co-opt intelligence agencies to go after political enemies or develop its own shadow units capable of extracting and analyzing damning data?

I don't know. Never underestimate humanity ingenuity when it comes to getting hands on a known treasure trove (of data or anything else). But one journalist as familiar as any outsider with the workings of post-9/11 intelligence agencies -- Kurt Eichenwald, author of 500 Days: Secrets and Lies in the Terror Wars -- thinks that the safeguards against abuse are sufficient:

With everything I know, and even as a die-hard believer in civil liberties, I can tell you that the program makes sense. Yes, people can rightfully be concerned about their privacy, but there are so many protections in place—including significant restrictions on how any information obtained from the data set can be used—that I don’t worry.

Think about it for a second: all of us submit much more personal information to the government every year in our tax returns. We disclose the cost of our medical bills, how much we spent on computers or copy paper, child support, and on and on. And unlike the data collected for this portion of the Stellar Wind program, that personal information can be studied minutely and directly by a government employee.

If this program were just for giggles, there would be plenty of reason for rage. And I won’t deny that people have the right to be upset; this is not a situation where everyone will agree. But what I do know is that the collection and analysis of this information have led to the disruption of significant terrorist attacks. And it’s certainly hard to say that doesn’t matter.

Eichenwald thus also accepts claims that the vast metadata collections have been instrumental in preventing terrorist attacks. NSA Director Keith Alexander claimed in a Senate hearing yesterday that the program had disrupted "dozens" of attacks -- the kind of claim that gives some of us flashbacks to unsubstantiated claims that torture also yielded information preventing attacks. One good outcome of the Snowden disclosure is that Alexander has promised to furnish evidence backing up that claim.

UPDATE: The NSA is now promising to release information about terrorist attacks thwarted by its programs. Assuming that their evidence holds up better than the terror apologists, evidence that current methods have stopped attacks would not necessarily make it clear whether more restricted data collection would have stopped the stopping of those attacks.