And this map does not show the phonebank/barnstorm hosts outside of the US. My friend in Vancouver, Canada (BC for Bernie), had so many people in his tiny apartment two weeks ago that one guy was phoning from the bathtub.
They connect to the Bernie campaign website which dials New York voters. Many people want to support Bernie, but they don't realize that they have to register to vote and they have to show up at a caucus.
The phoners also reached people returning from the massive Bernie rally in Brooklyn.