EtihadThe Department of Homeland Security's ban on large electronics is now officially in effect. The ban, which was announced on Tuesday, forbids passengers from bringing any electronic devices larger than a cell phone into the cabin of certain flights to the US. Airlines were scrambling for answers to the operational nightmare created by the ban, after getting just 96 hours to comply or risk losing their license to fly into the US.There are still a lot of unanswered questions about the ban's motives, its effectiveness at deterring a terrorist attack, the huge loopholes left open by the Trump administration, and how airlines are expected to comply with the ban and a Federal Aviation Administration prohibition against checking lithium-ion battery devices. Here's what we know so far. What's the ban? The ban requires passengers to place all electronic items larger than a cell phone in their checked luggage so the devices cannot be accessed in flight.