Washington ( CNN ) -- A 21-year-old man who admitted posting online threats against the creators of the animated TV series `` South Park '' was sentenced Thursday to 25 years in prison . Zachary Adam Chesser encouraged violent jihadists to attack `` South Park '' writers for an episode that depicted the Prophet Mohammed in a bear suit , court documents said . He posted online messages that included the writers ' home addresses and urged online readers to `` pay them a visit , '' the documents said . `` His actions caused people throughout the country to fear speaking out -- even in jest -- to avoid being labeled as enemies who deserved to be killed , '' U.S. Attorney Neil MacBride said . `` The fact that a young man from Northern Virginia could support such violence and terror is a sobering reminder of the serious threat that homegrown jihadists pose to this country . '' Chesser pleaded guilty in October to providing material support to terrorists , communicating threats and soliciting others to threaten violence . The three charges carried a maximum sentence of 30 years in prison . `` I accept full responsibility for all of my actions , and I would like to take the opportunity to express remorse , '' he said in court . Chesser , who was born in the United States , converted to Islam in high school . U.S. District Court Judge Liam O'Grady told Chesser he had made a big leap from being a high school athlete to a traitor . Chesser also admitted that he tried to go to Somalia to join Al-Shabaab , an Islamic militant group that the United States considers a terrorist organization .
NEW : A `` South Park '' episode depicting Mohammed in a bear suit upset Chesser , documents say . NEW : Chesser admitted posting show writers ' addresses and urging readers to `` pay them a visit '' on the Internet -- which he did not do. He faced a maximum of 30 years .