Consternation has arisen among politicians, even including demands for the recall of parliament, at the prospect that the government might soon bring in “Covid passports”. These would enable the bearers to prove, to whomever it might concern, that they had the necessary two vaccinations required for relative immunity. The prime minister has talked about them being obligatory, for instance, for those wishing to enter night clubs and similar venues; but the scope for expanding this requirement is almost limitless. Could we get to the point where police officers could demand proof of vaccination from anyone walking in the street?