Distributing Bibles.
It's difficult imagining anything more dangerous in an islamist country/area.
They were part of a sailing race and had decided to make a side trip through the Indian Ocean. They sailed a lot and had sailed round the world a couple of times before that.
The couple always brought Bibles with them, not for distribution to the Islamic world, but to give to poor churches that they encountered when they stopped at port. They had been doing this for several years; it was a sailboat, so they probably didn’t have thousands of Bibles with them, but just a small number to distribute to these churches which are often too poor to buy their own for their congregations.
The Muslims captured them out on the seas and had no idea what they were doing. It just looked like an opportunity to make money. And now that they know we’re so weak, an American flag sure wouldn’t discourage them.
I think the correct term is more ignorant. Stupid is as stupid does!!!