Ps took this suit on behalf of customers of text messaging-the sending of brief electronic messages between two or more mobile phones or other devices, over telephone systems, mobile communications systems, or the Internet. Ds are four wireless network providers-AT&T, Verizon, Sprint, and T-Mobile-and a trade association, The Wireless Association, to which those companies belong. Ps allege that Ds in violation of section 1 of the Sherman Act, 15 U.S.C. §§ 1 et seq., conspired with each other to increase one kind of price for text messaging service-price per use (PPU). Ps eventually passed the Twombly 'plausibility' test in order to avoid dismissal. The complaint alleges a mixture of parallel behaviors, details of industry structure, and industry practices, that facilitate collusion. Ps put forth a pair of emails from an executive of T-Mobile named Adrian Hurditch to another executive of the firm, Lisa Roddy. Hurditch was not a senior executive, but he was involved in the pricing of T-Mobile's products, including its text messaging service. The first of the two emails to Roddy, sent in May 2008, said 'Gotta tell you, but my gut says raising messaging pricing again is nothing more than a price gouge on consumers. I would guess that consumer advocates groups are going to come after us at some point. It's not like we've had an increase in the cost to carry message to justify this or a drop in our subscription SOC rates? I know the other guys are doing it, but that doesn't mean we have to follow.' The second email, sent in September 2008 in the wake of a congressional investigation of alleged price gouging by Ds, said that 'at the end of the day we know there is no higher cost associated with messaging. The move [the latest price increase by T-Mobile] was collusive (sic) and opportunistic.' The misspelled 'collusive' is the heart of Ps’ case. The trial court granted summary judgment, and Ps once again appealed.