See http://nypost.com/2014/07/24/solar-flare-nearly-destroyed-earth-two-years-ago-nasa/. According to the New York Times NASA now reports we very narrowly missed a CME event in summer 2012 that could have set the Earth back centuries. There may be a touch of sensational journalism, but the dangers are real. Apparently the odds are still quite high that if could happen again (12%).
We are moving past the peak of the solar cycle to less active solar times, so we may be lucky. Such an event last happened in the mid 1800s before wireless, PCs, GPS and satellites. Let's hope we are now more prepared for such an eventuality. Scary stuff.