This week's case continues a trend I've written about before: more courts are declining to certify class actions where they will not be able to ascertain class membership based on the evidence before them.

In Sethavanish v. ZonePerfect Nutrition Co., No. 12-2907-SC, 2014 U.S. Dist. LEXIS 18600 (N.D. Cal. Feb. 13, 2014), the plaintiff sued ZonePerfect alleging that it had fraudulently marketed its nutrition bars as "all natural" even though they contained a number of artificial ingredients.

When the plaintiff moved to certify a class, ZonePerfect pointed out one very large problem with her proposal: it did not sell its nutrition bars retail. From a merits standpoint, that was not an insurmountable hurdle. But it meant the plaintiff would have a very difficult time identifying other members of the class.

As it turns out, the Northern District of California had precedent on either side of the question of whether administrative difficulty can preclude finding an ascertainable class. But in this case, the more recent line of cases holding that ascertainability requires evidence proved more persuasive:

The Court finds the reasoning of Carrera and Xavier more persuasive than that of Ries and Astiana. While the former line of cases may restrict the types of consumer classes that can be certified, they do not bar certification in consumer class actions altogether. For example, in some cases, retailer or banking records may make it economically and administratively feasible to determine who is in (and who is out) of a putative class. Moreover, even though there is no requirement that a named plaintiff identify all class members at the time of certification, that does not mean that a named plaintiff need not present some method of identifying absent class members to prevail on a motion for class certification.

(Emphasis added.)  So, the takeaway from this case: don't forget to look at what would actually be required to identify class members. If it's not feasibly, you may have a strong defense against certification.