The worst offenders are China, North Korea, Belarus and Russia, followed by the UK, the US, and Singapore.
The two crucial facts about the information gathered under an electronic police state are these:
1. It is criminal evidence, ready for use in a trial.
2. It is gathered universally and silently, and only later organized for use in prosecutions.
In an Electronic Police State, every surveillance camera recording, every email you send, every Internet site you surf, every post you make, every check you write, every credit card swipe, every cell phone ping... are all criminal evidence, and they are held in searchable databases, for a long, long time. Whoever holds this evidence can make you look very, very bad whenever they care enough to do so. You can be prosecuted whenever they feel like it - the evidence is already in their database.
Perhaps you trust that your ruler will only use his evidence archives to hurt bad people. Will you also trust his successor? Do you also trust all of his subordinates, every government worker and every policeman?
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.