“Although the government acknowledged at oral argument that not all rock throwing amounts to a “serious nonpolitical crime,” the Board’s fleeting assessment of Berhane’s situation offers little explanation for why he falls on the wrong side of the rock-throwing line. And although the Board’s definition of a “serious nonpolitical crime” is well established (whether the criminal nature of the conduct outweighs its political motives), the Board and the courts of appeals have not issued any decisions (to our knowledge) in which rock throwing was the principal criminal act. For these reasons and those elaborated below, we vacate the Board’s decision and remand the matter to the Board for further consideration and further explanation of its position.” Berhane v. Holder, June 4, 2010.