Tim Cook doubled down on his privacy position this morning, refusing to give in to the FBI’s demands to create an iOS backdoor so the bureau can unlock the San Bernardino shooter’s iPhone.

In an email to employees with the subject line “Thank you for your support,” the Apple CEO says the company’s battle is about much more than a single iPhone or single investigation.

Donald Trump has slammed Apple for its refusal to unlock gunman Syed Rizwan Farook’s iPhone 5c after being requested to do so by the FBI.

“Who do [Apple] think they are? They have to open it up,” Trump told Fox and Friends when asked about Apple’s responsibility to help with the investigation following the attack in San Bernardino, California, which killed 14 people.

The case involving San Bernardino shooter Syed Rizwan Farook’s iPhone 5c and whether Apple should help unlock it has brought the company’s stance regarding strong encryption to the forefront.

Since this privacy-versus-security debate isn’t going away anytime soon, here’s what you need to know about it so far — and why it’s a much, much bigger issue than just one legal case.

In December 2015, Syed Rizwan Farook shot up an office party in an apparent terrorist attack in San Bernardino, California. He may have coordinated the attack on an iPhone 5c.

Since then, authorities have been trying to decrypt the device. And now, a U.S. magistrate is trying to force Apple to unlock it.