Apple routinely responds to law enforcement requests for data stored in iCloud, providing data on more than 1,400 accounts to US police in the first half of 2015. That practice is common across the industry, particularly among web-service-focused companies like Google and Microsoft. There have been some cases where that access has been challenged, most notably a Microsoft case challenging US law enforcement's right to seize data held on a server in Ireland, but in most cases a court order is sufficient to retrieve the data.

In the current case, Syed Farook's iCloud backups provide the most comprehensive information available on how Farook used his phone in the months leading up to the attack. The backups halt six weeks before the attack, and investigators have drawn fire for committing a forensic error that made it impossible to retrieve more data through the iCloud system.