I've lurked in slash fandom on LJ since 2003. I remember when LJ was down for hours or more and fans were desperate to get in touch with each other. In January 2005 it was down for over 24 hours. After it, people used icons that said "I survived the Great LJ Blackout of 2005" (or something similar) and posted funny lists about what they did during the blackout. (With things like "Refresh. Refresh x 100. Give up and go spend time with your family and friends. After 15 minutes, remember that your family and friends are boring and that's why you have LJ. Refresh.")
It makes me feel weird to see that people on Facebook are doing the same thing now. Being addicted to internet services used to not be mainstream! These are ordinary people!
Other things have changed, too -- I'm no longer as dependent on LJ as I used to be. There's Dreamwidth, now, and fanfiction (in my fandoms) is posted (also) elsewhere, for example the Archive of Our Own. A lot of fans are on Twitter or Tumblr or some other sites.
I guess this is only what I've witnessed (except for the Facebook phenomenon, possibly) -- do you feel the same?