Consumer data breach class actions, for all of their popularity on dockets and especially in headlines, can make difficult cases for plaintiffs. Issues like standing and damages often keep these cases from getting off the ground (as we have discussed previously), but we see far larger predominance problems looming for plaintiffs—chiefly in the area of causation. Companies in 2018 know how difficult a data breach can be to prevent, detect, and fix. These same difficulties can also flummox plaintiffs trying to sue companies in the wake of a data breach.

Consumer data breach cases, particularly those resulting from large breaches, involve a complex chain of independent actors. Take a payment card attack such as the one that occurred at Target in 2013. Through a virus sent by email to a vendor that had access to Target’s store-level computer network, hackers installed a program on virtually all of Target’s point-of-sale consoles that customers use to swipe their payment cards. That program copied information from the card—things such as the card number, expiration date, and CCV codes––and stored it on Target’s network. Then, the program sent the copied data through a chain of servers in different jurisdictions to the hackers. The hackers (or others who had purchased information from the hackers) were then able to sell the payment card data on the so-called “dark web.” A prospective purchaser would buy card information and have it printed on a counterfeit card, which could then be used to make purchases. Thieves obtained stolen information on 40 million payment cards using this method without ever necessarily setting foot in a Target store.

But hackers can use several other methods as well. A local thief can install a “skimmer” device that copies data from payment cards. These devices are often installed on gas pumps or ATMs. A single rogue employee could copy information from a business’ customers’ cards, or the employee could steal information from the business records (paper or electronic). Hackers can also attack other parts of the payment card infrastructure, such as payment card processors or issuing banks. Online stores can be hacked directly, and hackers can also obtain payment card data by accessing a consumer’s computer and stealing information stored on it. The personal data stolen from Equifax would allow criminals to open fraudulent payment card accounts. If these weren’t enough, a deft pickpocket can still steal a physical card.

While these various kinds of attacks can be prevented or interrupted, most of these breaches and thefts remain secret until fraudulent cards appear on the market or a pattern of fraudulent charges begins. Once fraudulent cards or charges appear, banks, processors, or the card associations (such as Visa and MasterCard) can look for common characteristics in the fraudulent charges: Did the customers all shop at a particular merchant at a particular time? Was the customers’ data routed through a common processor that could have been hacked? Are the fraudulent cards being used in one geographical area, or are they dispersed throughout the country? Are the fraudulent cards being used exclusively online? The answers to these questions allow industry and government investigators to narrow the list of possible causes of the breach.

Further complicating matters, stolen information or cards can be sold and resold on the black market before appearing in commerce. While thieves usually try to move quickly before the cards are cancelled, some thieves are sophisticated enough to balance speed with avoiding detection—they know a spike in fraud might trigger an investigation.

At first blush, the investigation of a data breach sounds much like how the CDC might go about tracking a salmonella outbreak to a particular food item. This analogy is attractive, but ultimately unsatisfactory for a few reasons:

• For one thing, there are too many overlapping breaches to draw neat causal lines. Because criminals prefer to remain anonymous, and companies suffering hacks are not anxious to publicize them, accurate records of data breaches are hard to obtain. But one estimate we reviewed suggested that there were nearly 180 million records at risk in known data breaches in 2017 alone. In other words, we know thieves stole more than one record for every two people in the United States in a single year. And that number does not include the three billion records stolen from Yahoo! across several years, or the nearly limitless number of records made vulnerable through the Heartbleed bug. This constant flow of breaches and thefts results in a constant flow of fraud. Large breaches cause fraud to spike, but accurately tying a particular instance of fraud to a particular breach is very difficult.
• While a patient suffering a medical condition will seek help, a data breach victim might not even know he or she has been affected. A payment card breach can lie dormant for a long time. Not only do thieves strategically time their use of stolen payment card information, they also use other personal information (such as Social Security numbers or access to an email account) to perpetrate fraud months or years later.
• Unlike disease-causing germs, criminal hackers actively avoid detection. Intrusions, data exports, and data transfers are all done with maximum secrecy. Moreover, a computerized attack can come from anywhere in the word through a lengthy chain of anonymized servers in different jurisdictions.

The complexity of tying a particular breach to a particular instance of fraud has led leading security journalist Brian Krebs to write, “All that said, it’s really not worth it to spend time worrying about where your card number may have been breached, since it’s almost always impossible to say for sure and because it’s common for the same card to be breached at multiple establishments during the same time period.” Finding the actual perpetrators of a breach will often be impossible, and in the present technological and legal environment, plaintiffs almost universally resort to circumstantial proof.

A company that is a victim of a data breach should be aware of these complex problems in defending against class claims. Consider a traditional negligence claim, which requires the plaintiff to prove that a breach of duty proximately caused the plaintiff’s injury. Plaintiffs often assert that any fraud happening after a breach happened because of the breach, but that conclusion is not only a logical fallacy, it should be legally insufficient. And chances are that a particular card has been the subject of more than one breach.

The Eleventh Circuit hinted at how important information about other causes can be in a data breach case. In Resnik v. AvMed, Inc., the court reversed dismissal of a complaint alleging that the plaintiffs suffered identity theft after a laptop with their personal information was stolen. The plaintiffs in that case had extensively alleged that they took a wide range of preventative measures to keep their identities safe. These allegations were taken as true for purposes of the appeal and “[h]ad Plaintiffs alleged fewer facts, we doubt whether the Complaint could have survived a motion to dismiss.” The Middle District of Alabama expanded on the Eleventh Circuit’s discussion in Smith v. Triad of Alabama, LLC, where (even though it certified a class), the court recognized that proving causation “may require a review of any prior thefts of each class member’s identity” and would involve member-by-member mini-trials.

As more data breach cases are filed—and especially as more of them get to the summary judgment and trial phases of litigation—plaintiffs’ theories will mature. In the meantime, however, companies should seek to understand the complex chain of events that occur before, during, and after a data breach. Not only will this information help companies secure their own systems against a breach, but it will also guide them in developing a strategy to oppose class certification. The plaintiff’s discovery efforts will be driven towards showing that the breach had a simple cause and had relatively uniform effects on a homogenous population of class members. To counter this narrative, companies must identify and discover variations within the plaintiff’s proposed class.  Instead of automatically adopting a passive, defensive posture, companies should consider being more aggressive in developing a counter-narrative. In appropriate circumstances, this could include investigation into preventive measures the named plaintiffs did or didn’t take with regard to their information or data, other data breaches occurring at roughly the same time as the subject breach, and whether plaintiffs’ or class members’ data might have been exposed to multiple unrelated breaches.

Such strategies may even prove helpful in those jurisdictions (such as the Seventh and Ninth Circuits) that have found standing in data breach cases where plaintiffs’ stolen information has not actually been used, but is alleged to create increased risk of identity theft alone (see our post on that subject). While pointing out factual complexities of the breach and other contemporaneous but unrelated breaches might not suffice to defeat Article III standing, such proof could well be beneficial in showing that common factual issues do not predominate and that individualized proof will be necessary. The proven prospect of thousands of mini-trials on causation and damage might give even a class-friendly judge pause.

Courts are still figuring out how consumer data breach cases fit into traditional tort categories. The theories asserted and damage items claimed in data breach cases are always changing, and that trend should continue. An effective defense strategy in this environment requires staying on top of the evolving ways in which criminals are stealing, selling, and using data.