About six months ago I was contacted by Big Brother Watch, the civil liberties campaign group, and asked if I wanted to help with an investigation into the surveillance of critics of the government’s pandemic response by state agencies. Would I submit subject access requests to different Whitehall departments to see if I was among the critics of the government’s pandemic response who’d been monitored by the Counter Disinformation Unit, the Rapid Response Unit, the Intelligence and Communications Unit and the 77th Brigade?

I thought it unlikely, but decided to play along and on Monday night Big Brother Watch published its...