Jihadist web forums lit up on Tuesday with anti-American radicals celebrating Monday’s terrorist attack at the Boston Marathon, which killed three and wounded at least 170. According to SITE Intelligence Group, which monitors the online web activities of radical Muslim groups and individuals, “jihadists expressed their joy and hoped the blasts are acts of jihadi terrorism.” “We ask Allah that this is the start before the storm,” said one user on one Jihadist forum. “May Allah give you the glad tiding of Paradise for this joyous news.” Some forum users hoped a Jihadist group was behind the attacks. Others speculated...