In most repressive countries, government censors like to toil in the shadows, maintaining a cover of deniability as they block citizens’ access to information. It is gratifying to see that the Internet and Google are making their job tougher.

Four months ago, Google unveiled a tool that allows users to monitor the requests received from governments to take down material or report data on the users of their search engine and other services. This month, it released another tool that will expose less overt attempts by governments to curtail its various services, including YouTube and Gmail.

The new tracker shows how traffic on YouTube in Iran fell to zero after the disputed presidential election last year. And how YouTube traffic collapsed in Libya in January after it aired videos of demonstrations by families of murdered prisoners and videos of partying relatives of Col. Muammar el-Qaddafi, the Libyan leader.

The tracker shows the ebbs and flows of traffic but not the cause of disruptions  whether a government directive or a cut cable. Still, it adds an important new source of information.