Facebook really is a scourge. As a non-user, I find it rather disturbing how so many places these days just assume you use it, and as such, that is the main place they post information about scheduling, etc.
Google is similarly pervasive. As a non-user I run into doc, group, and hangout links that only work if you have a Google Account a little more than once per week. Posters are rarely even aware of the restrictions because everyone in their immediate circle has one.
I really like Maciej Cegłowski’s idea of a “right to delete.” It’s indefensible that services don’t let you remove your own information, or make you jump through arbitrary hoops of their choosing. Leaving Facebook was one of the best things I’ve done on the Internet.