He came to Norway at age 8 or 9 and stayed for a couple of years, during which time he gained Norwegian citizenship, Hansen said. He later returned to Somalia.
Al-Shabaab became quite popular among some Somali community groups in Norway from 2007 to 2009, Hansen said, "because they were wrongly seen as some kind of national resistance group."
Observers noticed contradictions between what the group said in its English- and Arabic-language messaging, he said, which contributed to ignorance within the diaspora about its real nature.
"But the terrorist attacks inside of Somalia made it easier for the wider ethnic Somali community to see that this was really a terrorist organization, and it distanced itself," he said, making it less popular now.
However, this development brought its own problems, Hansen said, and not just in Norway.
"What you have to look out for, also in the United States and the United Kingdom and all these other Scandinavian countries, are these small, small networks that are in one sense detached also from the Somali community leaders -- radicalized groups of youths and radical preachers, sheikhs, that go traveling around the various countries to try to incite," he said. "That's what we have to watch these days."