It has been touted as "the most important tech case in a decade".
But can Apple stop governments ordering it to hack its own customers' iPhones? And who holds the moral high ground among companies and governments when it comes to the battle between privacy rights and national security?
Last week, Apple chief executive Tim Cook told the FBI that his company would not co-operate with US authorities' requests to neutralise an iPhone security mechanism, even to help a terrorism investigation.
The FBI had captured the iPhone of one of the terrorists responsible for a lethal gun attack in California's San Bernardino last December. They wanted Apple to create a new bit of software that would disable the phone's 10-attempts-and-you're-out passcode security system. Cook told them to shove it.
"The implications of the government's demands are chilling," he wrote in an open letter to Apple's customers. "The government could extend this breach of privacy and demand that Apple build surveillance software to intercept your messages, access your health records or financial data, track your location, or even access your phone's microphone or camera without your knowledge.
"In the physical world, it would be the equivalent of a master key, capable of opening hundreds of millions of locks - from restaurants and banks to stores and homes.
"In the wrong hands, this software - which does not exist today - would have the potential to unlock any iPhone in someone's physical possession."
The FBI isn't backing down and has a court order on its side. If Apple keeps saying no, it could go all the way up to the Supreme Court, which may force the tech giant to hack its own phone.
The case has sparked worldwide interest and has divided views. Politicians and security chiefs have brandished Apple as the "friend" of "terrorists and drug dealers" and have threatened the company with court action or legislation.
"Who do they think they are?" thundered Donald Trump, the leading Republican presidential contender.
Supporters of Apple have been equally vocal.
"This is the most important tech case in a decade," said the NSA whistleblower Edward Snowden last week. "The FBI is creating a world where citizens rely on Apple to defend their rights, rather than the other way around."
Who has the moral high ground? Should an iPhone security system be circumvented to retrieve terrorist information? Or does the risk of all iPhones becoming permanently hackable make such a foray reckless and disproportionate?
"The FBI wants us to make a new version of the iPhone operating system, circumventing several important security features, and install it on an iPhone recovered during the investigation," said Cook.
"The FBI may use different words to describe this tool - but make no mistake: building a version of iOS that bypasses security in this way would undeniably create a backdoor.
"And while the government may argue that its use would be limited to this case, there is no way to guarantee such control."
Is Tim Cook really standing up for us? Or is it just all about business?
On one hand, publicly defying US authorities on this issue makes strategic business sense.
Security and data privacy is one reason why people buy iPhones over rival handsets. Apple cannot be seen to cave in easily to such requests.
The company has an even bigger business concern: China. If it co-operates with the US government in creating backdoor keys to its own iPhones, Chinese authorities will bristle at the thought of popular smartphones within China being accessed by US spies. China, lest it be forgotten, is a bigger iPhone market than the US.
The reverse espionage-laden scenario is also at issue for many US companies. If the US gets Apple's security secrets, China will demand similar access. That could spell a lot of trouble for US and European industrial sensitivities.
Some politicians recognise this as a doomsday scenario.
"This move by the FBI could snowball around the world," said Democratic Senator Ron Wyden, a member of the US Senate's Intelligence Committee. "Why in the world would our government want to give repressive regimes in Russia and China a blueprint for forcing American companies to create a back door?"
But while some cynics say that this is just a tactical commercial ploy by Apple, others point to Cook's track record on privacy issues. More than other company executives, the Apple chief executive has form on the topic.
In a Sunday Independent interview last November, the Apple CEO was adamant that Apple would not introduce any form of 'back door' into iPhone or iMessage security systems, no matter who told the company to do it.
He was speaking against the background of the company's outspoken stance against a proposed UK government surveillance law that could compel Apple and other tech companies to water down encryption standards in the name of enhancing Britain's anti-terror capabilities.
"Any change made would contradict the UK government's view that they would not weaken encryption," he told the Sunday Independent at the time. "I have every faith that through this process of the next year, give or take a year, that the bill will become very clear."
He has also spoken out against other tech companies for their more liberal approach on privacy matters.
"Our privacy is being attacked on multiple fronts," he told a privacy conference last May. "I'm speaking to you from Silicon Valley, where some of the most prominent and successful companies have built their businesses by lulling their customers into complacency about their personal information.
"They're gobbling up everything they can learn about you and trying to monetise it. We think that's wrong. And it's not the kind of company that Apple wants to be."
Can Cook talk on our behalf, though? Is the head of a company the right person to be affecting decisions on society's behalf around such universal issues?
Cook takes a view that being the head of a company and being a civil liberties advocate are not mutually exclusive in the way they may have once been.
"Business has an important responsibility to society," he said at a conference in September. "That responsibility has grown markedly in the last couple of decades or so as government has found it more difficult to move forward."
This is an interesting point.
In Ireland, there are few state bodies or government entities which promote data privacy in any active way.
Usually, elected or representatives bodies are the ones fighting for restrictions on privacy, rather than extensions of it.
For example, it took a small campaigning group (Digital Rights Ireland) to bring down a law requiring telecoms operators to hold details of our phone calls and texts for two years.
The European directive on which the law was based was ultimately struck down by the European Court Of Justice.
And looking through the political parties' election manifestos, just one party (the Greens) has any specific policies on privacy. Most do not even mention the issue in passing throughout their entire manifestos.
In the US, there are far more politicians to condemn Apple than to applaud it.
"Apple chose to protect a dead Isil terrorist's privacy over the security of the American people," said US senator Tom Cotton. "It's unfortunate that the great company Apple is becoming the company of choice for terrorists, drug dealers and sexual predators of all sorts."
Ultimately, many will hope that such hyperbole does not win out.