Immigration advocates gather like clockwork outside Seattle's King County International Airport to witness deportation flights and spread word of where they are going and how many people are aboard. Until recently, they could keep track of the flights using publicly accessible websites.
But the monitors and others say airlines are now using dummy call signs for deportation flights and are blocking the planes' tail numbers from tracking websites, even as the number of deportation flights hits record highs under President Donald Trump. The changes forced them to find other ways to follow the flights, including by sharing information with other groups and using data from an open-source exchange that tracks aircraft transmissions.
