donottrack.usは安全ですか？

Helps you to opt out from many web tracking sites. Do Not Track is a technology that enables users to opt out of third-party web tracking, including behavioral advertising. At present a user cannot opt out of many of the hundreds of tracking services and advertising networks; those that do allow opting out each require setting (and not deleting!) an opt-out cookie. Much like the popular Do Not Call registry, Do Not Track provides users with a single, persistent setting to opt out of web tracking.