> Messaging applications are increasingly making use of end-to-end security mechanisms to ensure that messages are only accessible to the communicating endpoints, and not to any servers involved in delivering messages.

You have to put trust in the app (and the company that owns that app), though.

In twitter, I type a message in plain text. The twitter app encrypts it and sends it to the recipient. I am trusting Twitter to not encrypt it twice, once with my key and once with there's and capturing their copy in flight.

With current trends at Twitter, I wouldn't trust them an inch.