This tweet was in response to Apple not unlocking two iPhones that were part of an investigation into a fatal shooting at a naval base in Florida last month.
The incident occurred when three Saudi trainees at opened fire and killed three US Sailors on 6 December, 2019.
US Attorney General William Barr said that Apple failed to provide assistance in the case however, Apple rejected the claim saying:
Our responses to their many requests since the attack have been timely, thorough and are ongoing,
This is the second time something like this has happened. Back in 2015, there was a mass shooting in California where 14 people killed and 22 injured and Apple back then refused to unlock the shooters iPhone.
Although the company provided Gigabytes of data from the shooters iCloud account and helped with the investigation, Apple refused to unlock the iPhone or provide a backdoor to do so.
Since, iPhones are basically used by the general public and they now contain their most sensitive data such as medical and financial records, making a backdoor into them and giving others access would put that private data at risk.
However, the US government reportedly paid another company $1 million to decrypt the device.