At least in America, is that few listen to anyone and actually BELIEVE them..There is no trust...
No one thinks about ANYTHING beyond the confines of there own cozy little lives and familys..In short if it doesn't affect people DIRECTLY, no one even realizes that "something" is happening, much less something terrible that will affect EVERYONE.People are self-absorbed.
How it happens?
People like Alex Jones, have been trying to get news like this across for years.But unfortunately he and most others have been mostly drowned out and discredited by "media".Its to easy to discredit someone by simply labeling them with some kind of "phobia" or saying they are a "conspiracy theorist".
People forget there history...A very basic concept that we are mostly (around THE WORLD if I'm not mistaken)taught when pretty young..That is basically that if you ignore history you are destined to repeat it.
People tend to not want to be labeled as "crazy" so they are very skeptical of anything that goes against government idealism,social engineering, or takes them out of there "comfort zone".
People do not think for THEMSELVES.....They are mostly puppets!