In an emergency situation (e.g., stuck on a snowy mountain), I would prefer for my communications to have zero privacy. The needs of business are on the opposite end of the spectrum.
But are you really going to access your Facebook account and or start Twittering with your smart phone and hope that someone knows and or cares about your predicament or are you going to call the Emergency Services such as the Police, Mountain Rescue or Coast Guard? If battery power or cell service range is spotty then an SMS to your Twitter page might be worthwhile, but would you attempt to call the emergency services first and risk the last of the battery power on the phone?
Opening a browser page to login into the Facebook account on the phone will probably draw more power on the smartphone than making a voice call or sending an SMS.
The general rule stands: I'd prefer zero privacy in most emergency situations. You brought up business, but their needs run opposite to my needs in an emergency. Let's assume battery power is not an issue, that I've already contacted Mountain Rescue, and that I feel like I'm dying. So then, I have the opportunity to use email, text, Facebook, etc. Ideally, I'd prefer to have a live broadcast to the entire world if I could. Facebook and Twitter would be about the closest thing at that moment with my humble little smart phone. If you could present another system that comes closer, then I'm all ears, but I haven't heard anything that's much better.