Tech giant Apple is staring down the FBI over the agency’s request to access encrypted data on a user’s iPhone.

In this particular case, which is being called one of the most important tech cases of the decade, the FBI is looking for a "backdoor" into the iPhone of San Bernardino shooter Syed Rizwan Farook, who killed 14 people and injured 22 more in December.

Apple is refusing to open that "backdoor," arguing that it would violate its users' security.

It sent the follow message to customers on Wednesday afternoon.

Apple - apple.com

A U.S. judge ordered the company to invent technology that would circumvent the iPhone's encryption system on Tuesday. in his statement to customers responding to that order, Apple CEO Tim Cook described the importance of encryption and the "chilling" implications of the federal government's demands. Though the FBI insists that it would only use the backdoor to access data on the Farook's iPhone, Apple worries that the technology could jeopardize the privacy and security of iPhone users around the world.

Though the FBI can already search through an individuals personal data on their phone or computer with a warrant, this case differs because the FBI is seeking help from Apple to bypass its own encryption system.

Cook wrote that Apple has complied with the FBI's requests, subpoenas, and search warrants at multiple points throughout their investigation into the San Bernardino shooting. But the latest request and legal rationale used to justify the court order goes a step too far, Cook says:

"We have great respect for the professionals at the FBI, and we believe their intentions are good. Up to this point, we have done everything that is both within our power and within the law to help them. But now the U.S. government has asked us for something we simply do not have, and something we consider too dangerous to create. They have asked us to build a backdoor to the iPhone."

There have been ongoing conversations about the relationship between tech companies and the federal government, specifically concerning cooperation in criminal cases. President Barack Obama recently met with leaders in the tech industry, urging them to put forth resources in the fight against terrorist organizations such as ISIS. The debate over encryption has caused controversy, however, as critics feel that the government should rely on legislative action through Congress in order to obtain encrypted information.