In Mazza v. Am. Honda Motor Co., 666 F.3d 581 (9th Cir. 2012), the Ninth Circuit Rule 23 predominance was defeated where many (or even most) class members “were never exposed to the allegedly misleading advertisements” (666 F.3d at 597) because the defendant subjected only a small segment of an expansive class of car buyers to misleading material as part of a “very limited” advertising campaign (id. at 595).  This decision raised questions about how federal courts in the Ninth Circuit would actually evaluate UCL claims when faced with reconciling In re Tobacco II and Mazza.  In Ruiz Torres v. Mercer Canyons Inc. (9th Cir. Aug. 31, 2016), a wage & hour suit in which the District Court certified a class, the Ninth Circuit analyzed Mazza in a manner demonstrating that it may be constrained in its application moving forward.