Tony Blair's think tank, as well as a few others, want us all to have a contact-tracing app on our smartphones because they could offer an "escape route" from the crisis.
Contact-tracing applications work by logging every person that a smartphone comes in close contact with another who also has the app - who also has the app!!! That's why we all need one. So, if one person is diagnosed with Covid-19, all those who are at risk can be notified automatically.
It's all good - so far.
But if someone, Bob, tests positive and symptomatic they should be isolated there and then, not let out to roam - this is (should) already be being done. The app could then, in theory, get in touch with all those Bob had been in contact with during the time it is 'thought' he might have been symptomatic. How long is that - hours, days? And during that time how many people did he come in contact with and how is 'contact' defined?
Bob is a decent bloke who is following the rules. He only went out to the supermarket during a quiet time to get some food. He was only close to about 20 people and only then for a few seconds, but the app has 'clocked' them all. The 20, and their households, go into lockdown and after testing everyone two of them are found to have the virus.... the process starts again.
So that could be 40+ tests just from Bob, and then 40+ more for each of his infected contacts. That's over 120 tests just from Bob, assuming nobody else gets the virus. If the virus is as infective as is presumed it only takes a few more ripples for the tests to be in their thousands. If there is a Bob in every area of the country we are looking at tens of,millions of tests, which is totally impractical.
There will be millions of people self-isolating or roaming about untested and worried sick that they might be infected because the 'app' said they had been in 'contact'. Panic, and God knows what else, would ensue.
There are times when we can have too much information. Also, tests are only valid at the time they are taken. Someone given the all-clear can catch it only hours after and not know. They then do a Bob....
The other big worry, probably more of a long-term worry, is when will these apps be deactivated - completely nuked? If that does not happen then we can be 'traced' forever and by agencies we are not even aware of. Sorry Tony, but I am staying app free.