The main objections to vaccine passports in England aren't privacy, they're that it discriminates against those who refuse to get vaccinated.
>And you don't have to show your vaccine passport if you, um, never go outside again.
You'd have to show your vaccine passport if you want to partake in proportionately high risk activities where you not only have risk to yourself, but you also pose a risk to others. And it's [almost] always places you have to take ID anyway, to prove your age.
Why should those who chose to not do the socially responsible thing of getting vaccinated, get to amplify the risk to those who do?
Plenty of Canadians, like myself, have huge objections to the privacy implications of our passport program.
What's ironic is that people who usually call out slippery slope as being a fallacy are participating in the fallacy of cherry-picking. Because slippery slope is only a fallacy when there is no prior evidence of the proposed events occurring, and 99.9% of the time people say "that's a slippery slope", it's in response to events that are similar to past events.
This is a classic demonstration that "slippery slope" isn't a fallacy.
First you need a driving license. Privacy conscious people objected. You don't need to show your driving license to drive, was the response, only if you break traffic laws or get into an accident. There's no one using it to track everywhere you go or anything.
Then comes the vaccine passport. Privacy conscious people object. Now the response is, hey, you already have to show your driving license if you get pulled over for speeding, what's the difference? And you don't have to show your vaccine passport if you, um, never go outside again.
Meanwhile we now have ALPR cameras recording the location history of every vehicle on the roads. Because some slopes are actually slippery.