Answer:
By saying that invasion of privacy has been "democratized", Walter Kirn means that the invasion of privacy has become a normal thing. And this democratization is not done by a single dictatorial government, but rather by the same people who are also equal citizens with the rest of the people.
Explanation:
Walter Kirn's article "Little Brother Is Watching" for the New York Times Magazine laid emphasis on how the issue of privacy has been completely changed from previous times. Everyone can now have access to anyone's details and whereabouts at the click of a button. The knowledge to hack computers, personal details and even firewalls and databases are all within grasp of everyone. And the most scary part of it was this isn't done by the government but rather by the very same citizens of the country. And this invasion needs no government back up as normal citizens can easily gain access to all details. Kirn said this "democratization" of invasion of privacy is something that possess a threat for everyone's security.
