For years now, WhatsApp has been one of the main methods that younger users communicated with a smartphone and despite having been bought by Facebook, it appears its business as usual. For WhatsApp, that means offering new users a year's worth of free service and then a scant subscription fee after that, with the idea that if you can hook millions upon millions of users then they're unlikely to move away from your service. After all, if all of you're friends and family use WhatsApp as their main way of chatting online, you're a lot more likely to use WhatsApp than anything else. No service is perfect though, and when WhatsApp experience some big outages some time ago, a competitor by the name of Telegram rose up to fill in the gap, and the blue messaging app has become something of a thorn in the green messaging app's side, and now WhatsApp appear to be doing something about it.
Telegram rose to popularity when WhatsApp wasn't available for those looking to chat online, but since then it's become the de facto app for a lot of users that take their privacy seriously, with encryption and a vow to never hand over your information to the authorities when they come knocking. Now however, it would appear as though WhatsApp is trying to prevent people recommending Telegram when chatting through the app, or at least they are by blocking telegram.org, its home page. As users on Reddit have discovered, this behavior appears to intentional, decompiling WhatsApp version 2.12.370 finds code that refers to telegram.org or variations upon it as a 'bad host'. This then makes it impossible to click or copy a message that is identified as a 'bad host'.
If anything, this is something of a head-scratcher, really. If users really wanted to go and get Telegram set up on their device, they're more than likely to simply Google it or download it from the Play Store directly on their device. Targeting invites sent by Telegram through WhatsApp would make a lot more sense, but either way it looks as if WhatsApp is taking the fight to Telegram, if only in a small and somewhat confusing way.