Actually today you don't use cracking down on child abuse as a reason, you use the danger of the far-right. All the leading left-wing publications, New York Times, The Guardian, Washington Post, CNN, Vox have been running articles about how dangerous encrypted chat apps are:

> Why right-wing extremists’ favorite new platform is so dangerous. Telegram’s lax content moderation and encrypted chats make it a convenient tool for extremists.

https://www.vox.com/recode/22238755/telegram-messaging-socia...

> In collaboration with anti-fascist research group the White Rose Society, the Guardian has tracked McLean’s activity through the rabbit warren of largely unregulated Telegram groups and found that he describes a vastly different version of his intentions.

https://www.theguardian.com/australia-news/2021/mar/26/where...

> Far-right groups move online conversations from social media to chat apps — and out of view of law enforcement

https://www.theguardian.com/uk-news/2021/oct/14/telegram-war...

> White supremacists openly organize racist violence on Telegram, report finds

https://edition.cnn.com/2020/06/26/tech/white-supremacists-t...

> Are Private Messaging Apps the Next Misinformation Hot Spot? Telegram and Signal, the encrypted services that keep conversations confidential, are increasingly popular. Our tech columnists discuss whether this could get ugly.

https://www.nytimes.com/2021/02/03/technology/personaltech/t...

> A report this week found that the messaging app had emerged as a central hub for several conspiracy movements espousing antisemitic tropes and memes, including QAnon, as well as others on the extreme right promoting violence.

https://www.washingtonpost.com/technology/2021/01/15/parler-...