[londons_explore]

The engineers who worked on Chat at facebook likely had the same access... They had an employment contract which said that they were allowed to use their access to debug bugs and improve the product, but not to spy on their girlfriends DM's.

Netflix presumably had the same.

As long as that access is audited to ensure it really was being used only for the intended purpose, I'm fine with that.

Inspected 50 messages all from your test account: fine. Inspected messages from an account after that user contacted customer support citing a problem with messages: fine. Inspected messages from an account after that account fired off alerts to the devops team for causing segfaults: fine. Look at a random account: not fine. Dump messages from many accounts with a script: not fine, and rate limits should stop you after like 100 messages.