Someone has figured out that any iPhone 5S or later is susceptible to a bug which bricks your expensive iPhone into an expensive paper weight. They are trying to get people to ruin their iPhones with a "ad" that even looks like it could've come from Apple themselves. Apple posted a statement on their website the other day warning consumers, "Manually changing the date to May 1970 or earlier can prevent your iOS device from turning on after a restart." They say they are working on a fix. An upcoming iOS update will prevent this issue from continuing.
Now what if you, or a "friend", has already done this? Don't panic too much. We can fix this. Stop in today and get your phone working again!