Federal investigators say the two teenage suspects behind the deadly San Diego mosque attack were allegedly radicalized online through violent white supremacist ideology before carrying out the massacre that shocked California. According to the FBI, the 17 and 18-year-old suspects first connected online and exchanged extremist beliefs, hateful writings, and digital messages uncovered during the investigation. The case is now intensifying fears across America over online radicalization and the spread of extremist violence targeting religious communities.