A Chinese music student was convicted on Thursday of U.S. charges that he harassed an activist who posted fliers at the Berklee College of Music in Boston supporting democracy in China and threatened to report her activities to Chinese law enforcement.

A federal jury in Boston found Xiaolei Wu, 25, who sent the activist online messages saying he would chop off her hands and demanding she tear down her “reactionary posters,” guilty at the end of a four-day trial.