Sergei Udaltsov launched a hunger strike after a Russian court sentenced him to six years in prison for justifying terrorism through online posts.The ruling follows a separate conviction in absentia of Swedish citizen Christopher Forsbäck, who received a 20-year sentence for participating in the Ukrainian incursion into Kursk.While Forsbäck dismissed the charges as pathetic from Kyiv, human rights groups noted these cases highlight an intensifying crackdown on dissent by the Kremlin.