My brother @pdcull is advising his Brazilian slum outreach / disaster response org from New Zealand using Facebook and Whatsapp, while he studies and communicates with emergency managers across the country.
The mainstream social media platforms aren't the best, but sometimes you still have to use what's there even as you build the next generation of open tools.
The delicate balance of 'when to stay with the crowd and when to be a pioneer' is never quite the same for every person, I think.