> considering Snapchat is an encrypted app.

I can't find any claim by Snapchat that they are *end to end* encrypted. They probably only use https to encrypt the connection between the users phone and the server.

Most likely Snapchat can and does read all messages on the platform and proactively informs law enforcement and/or intelligence services.

Alternatively intelligence services have front / back door access to Snapchat servers.

Alternatively Snapchat uses something like CloudFlare to handle https encryption, in a way that lets CloudFlare and its NSA friends read everything that goes over the wire.