Prosecutors allege that 31-year-old Rajib Karim was communicating with a terror cell by coded e-mails and sharing details of his BA contacts.
Karim testified Tuesday that he was helping make a video about an organization called Jamaat-Ul Mujahideen Bangladesh because he believed it had been misrepresented as a terrorist organization.
He says he sent messages to his brother in code because he feared for his brother's safety. The defendant said, "The regime in Bangladesh is very brutal."
Karim has admitted helping produce a terrorist group's video, fundraising and volunteering for terror abroad.