I've just finished reading this, and fans of "Sir Henry" will be unsurprised to hear that it is both a thumping good read, and largely about the database state.
Discussed by Mr Porter himself here (there are no spoilers, so you can read safely):
Henry Porter: 'Why I write about the surveillance state' wrote:
The Dying Light is a political thriller, so why deploy characters better suited to the long vigil at a border crossing, or an undercover job in some distant embassy? The answer is that spies are familiar with the despotic instinct, have the necessary skills to outwit a government that has granted itself so many authoritarian powers and – crucially- are quick to understand that all communications and any information held digitally are compromised.
Spies are used to conveying information in the physical form - a letter or document that cannot be intercepted - and they know how to evade surveillance, even in a country like Britain where the authorities has given themselves powers to watch every street corner, monitor every car journey in real time and are about to seize access to all emails, Internet connections, text messages and phone calls. In these circumstances, the old tradecraft of the Cold War is very useful.