Family members of Venezuelan migrants who suspect their loved ones were sent to El Salvador as part of a rapid U.S. deportation operation over the weekend are struggling to get more information as a legal battle plays out.

Advocates have launched a WhatsApp helpline, opens new tab for people searching for family members, while immigration attorneys have tried to locate their clients after they went dark.

The sudden move caused confusion among family members and immigration advocates.

“This chaos is purposeful,” said Anilú Chadwick, pro bono director of the advocacy group Together & Free. “They want to exhaust people and exhaust resources.”