 How do Svan and his five fellow insurgents find out that the people of Earth no longer think of

Venusians as human?
DOUBLECROSS by JAMES Mac CREIGH Revolt was brewing on Venus, led by the descendant of the first Earthmen to land. "They had to acclimate themselves to Venus's climate. They think there will be hordes of immigrants from Earth, now that we know Venus is habitable. We have agreed that, if the Earth-ship returns, it means disaster for Venus. The six conspirators in Svan's old ground car moved slowly along the main street of the native town. Two Earth-ship sailors, unarmed except for deceptively flimsy-looking pistols at their hips, stood before the entrance to the town's Hall of Justice.
 They use a spy ray, which allows hem to listen in on a conversation happening on an official
 They are informed by fellow Venusian rebels, who themselves heard from the council.  They already know. Racism and prejudice runs rampant in all Venusian and Earth towns.  They intercept a galactic transmission, which explains it all.  They use a spy ray, which allows hem to listen in on a conversation happening on an official