In 2015, hundreds of thousands of people fleeing war and repression were trying to reach safe havens in Europe. From his home in Norway, Tommy Olsen decided to travel to Greece, a major gateway for migrants and refugees. He joined hundreds of volunteers  helping the new arrivals and later created an NGO, the Aegean Boat Report, which monitors the plight of asylum seekers in Europe.

Today, Olsen is a wanted man in Greece, caught up in a crackdown on refugees and people trying to defend their right to asylum.

“I didn’t know what I walked into,” Olsen says.

Mary Lawlor, the UN special rapporteur on human rights defenders, has condemned Greece’s harsh migration policies and the way its government is targeting activists like Olsen. But she says Europe as a whole is also to blame.

“The whole notion of migration is a dirty word now,” she says. “The whole notion of refugees is a dirty word now.”

This week on Reveal, reporters Dinah Rothenberg and Viola Funk from the Berlin podcast studio ACB Stories take us to Greece, where refugees and human rights defenders face legal and sometimes physical attacks from authorities trying to seal the country’s borders.