Turkey’s battle over Net censorship is heating up, with the government there reportedly blocking a method that let citizens sidestep a Twitter ban, the White House expressing “serious concern” over the ban, and Google reportedly refusing requests from Turkish authorities to take down YouTube videos that cast the prime minister in a critical light. Bloomberg cited Turkish newspapers in reporting that the Turkish government had blocked on Saturday a Google service that enabled citizens to tweet. Setting a PC or mobile device to use Google’s DNS IP address of 8.8.8.8 had let people slip past the ban (and graffiti displaying the phrase “DNS 8.8.8.8” was even spotted around Turkey, helping spread the word). But on Saturday the government prevented access to Google DNS, Bloomberg said.