In November 30, 2015, the Android WhatsApp client made links to another message service, Telegram, unclickable and uncopyable. Multiple sources confirmed that it was intentional, not a bug, and that it had been implemented when the Android source code that recognized Telegram URLs had been identified. (The word "telegram" appeared in WhatsApp's code. ) Some considered it an anti-competitive measure, but WhatsApp offered no explanation. In response to the 2014 Facebook acquisition, Slate columnist Matthew Yglesias questioned whether the company's business model of charging users $1 a year was viable in the U. S. . It had prospered by exploiting a "loophole" in mobile phone carriers' pricing. "Mobile phone operators aren't really selling consumers some voice service, some data service, and some SMS service", he explained. "They are selling access to the network. The different pricing schemes they come up with are just different ways of trying to maximize the value they extract from consumers. " As part of that, carriers sold SMS separately. This made it easy for WhatsApp to find a way to replicate SMS using data, then sell that service to mobile customers for $1 a year. "But if WhatsApp gets big enough, then carrier strategy is going to change", he predicted. "You stop selling separate SMS plans and just have a take-it-or-leave-it overall package. And then suddenly WhatsApp isn't doing anything. " The situation may have been different in countries other than the United States.