"In order for you to write a message to a Facebook friend from within Spotify, for instance, we needed to give Spotify “write access.” For you to be able to read messages back, we needed Spotify to have “read access.” “Delete access” meant that if you deleted a message from within Spotify, it would also delete from Facebook. No third party was reading your private messages, or writing messages to your friends without your permission. Many news stories imply we were shipping over private messages to partners, which is not correct."
It's become clear from engaging in this discussion that people aren't interested in facts or context, but have a chip on their shoulder about Facebook. Others have also been misinformed by inaccurate news stories.
I don't even use Facebook, yet it's pretty easy to understand the facts if you're actually interested in them.