Canary Mission is one of the oldest and most prominent of several digital advocacy groups that have intensified campaigns to expose Israel’s critics since the war broke out, often leading to harassment such as Sayed experienced. The people behind the site have kept their identities, location and funding sources hidden.

Reuters reviewed online attacks and abusive messages directed at scores of people targeted by Canary Mission since Oct. 7.

The site has accused over 250 U.S. students and academics of supporting terrorism or spreading antisemitism and hatred of Israel since the start of the latest Gaza conflict, according to the Reuters review of its posts. Some are leading members of Palestinian rights groups or were arrested for offenses such as blocking traffic and punching a Jewish student. Others, like Sayed, said they had just stepped into campus activism and were not charged with any crimes.