(JTA) – At least two synagogues in California evacuated during Shabbat services over the weekend as online trolls targeted Jewish congregations for the fourth straight week with fake bomb and other security threats.

At least 26 congregations in 12 states have received the threats, according to the Anti-Defamation League, which is raising alarm about the barrage. The organization believes the instigators are selecting their targets based on the availability of livestreamed services and other events, motivated by their desire to watch the congregations react to the threats in real time.

“This is...