With an alarming rise in cybercrimes, often including blackmail, police offer workshops for thousands of teenagers
What their attackers bet on is shame: in a conservative society, the horror of an intimate photo leaking, or rumours being spread, is enough to buy a teenage girls silence.
We didnt even know anyone could harm us through the internet, said Sharifa Oishee, a schoolgirl in Dhaka, Bangladeshs capital.
But research shows otherwise: teenagers are overwhelmingly the victims of an alarming rise in cybercrimes in Bangladesh, driven, as elsewhere, by the proliferation of smartphones and social media.
Police last month began training thousands of teenage girls to defend themselves against blackmail or harassment online. Girls and women make up 70% of the victims of cyber-harassment, according to authorities.
More than 10,000 girls have taken part in the workshops during April and May, with Facebook safety a key focus. Dhaka is the second most active city in the world for users of the social network, and abuse on its platform is the focus of more than 60% of all online harassment complaints to police.
Mishuk Chakma, of Dhaka polices cybersecurity and crime division, said: Sometimes the criminals superimpose faces of the girls on to the bodies of nude models or adult films stars to blackmail and defame them.