Anything 'can' happen, and to be prepared is one thing, even responsible.
To 'expect' that it will happen, is paranoia.
Edit: To relate a local experience. Remember Y2K? Twelve years ago a local guy built a backwoods bunker and moved his wife and young family onto it. He even convinced his younger brother and his smaller family into his plan.
Previously he sold everything he owned and turned it into fuel, generators, guns, bullets, water purifiers etc. They burned all their i.d.'s, birth certificates, passports... everything.
6 months later, after the world didn't end, they came back to civilization when their food started running out.
Edited by Likely Guy, 08 December 2012 - 03:50 AM.