When I left for Trieste last week, I decided to leave some vital data with the UK government: the pattern of my irises. Now, when I enter the country, my eyes are scanned by a science-fiction-ish kiosk and I get through faster than those other less fortunate foreigners. But I’m the one with the data trail for the government to pick at (then again, I’ve not been shy about revealing my identity in other contexts, such as my name, profession and contact details on the top of this very web page).