Worryingly, activists say there isn't much to stop the UK government if it does decide to use more invasive tracking measures.
Silkie Carlo, director at privacy group Big Brother Watch, said a clause in the UK's Investigatory Powers Act meant the government could track people's phone data secretly.
She wrote: "Extraordinary thing is, UK authorities could already be using phone data to track symptomatic/diagnosed people. There'll be no announcement if or when it happens. The powers are there in Investigatory Powers Act and compel total secrecy."
Part 3 IPA, s61. No pre or post notification, no publication, nothing. Total secrecy if this power is used. pic.twitter.com/PAosyTMkDU
— Silkie Carlo (@silkiecarlo)
March 22, 2020