The new proliferation of drones exposes how US defense isn't ready, industry insiders say. Kostya Liberov/ Libkos via Getty Images The US is vulnerable to drone threats and doesn't have enough protection, a detection firm warned. Military officials have made similar warnings, saying defenses are lacking. Drones are cheap and easy to field, creating a new challenge for civilian sites. The US isn't ready to detect and defend against hostile drone attacks, a detection company warned, echoing conc