Google has addressed a security concern with the Face Unlock system on its Pixel 4 smartphones, more than five months after the devices went on sale. In October 2019, a BBC News test found the Face Unlock system allowed access to a person’s device even if they had their eyes closed. Security researchers criticised the feature, as it could allow unauthorised access to a smartphone. Google updated the Pixel software on 6 April to address the issue. But the fix was not enabled by default on two Pixel phones tested by BBC News.