In our view, the most robust metric available is the number of times an agency or authority demand for assistance is instigated – in effect, a formal record of each occasion that the state has decided it is necessary to intrude into the private affairs of its citizens – not the extent to which those warranted activities then range across an ever-expanding multiplicity of devices, accounts and apps, access to each of which could be recorded and reported differently by each company (and indeed each agency or authority) involved.