Facebook's C&D letter [0] reminded me of how difficult it was to migrate my friends to Google Plus because the Facebook TOS prevented third party access to contact information and mass messaging. With the recent whistleblower testimony [1] I was thinking one of the most impactful decisions Congress could make would be enabling users to fully own their contact lists. Organic growth of alternative social media platforms would be easier if all it took was a click of a mouse to send all your contacts a message on your other platforms.
This is completely useless now that Google+ is dead (since 2019). However, as somebody who used Google+ back in 2011, part of the attraction was that the people who liked Facebook weren't on Google+. It was a good forum for geeks, techies, artists, writers, and musicians until around 2013 or so when Google decided to make all of their stuff part of Google+ (including YouTube).
It was a "ghost town" from a marketing viewpoint, but it was my ghost town.
[0] https://news.ycombinator.com/item?id=28801908
[1] https://news.ycombinator.com/item?id=28741532