I just saw an article about an extortion ring in Australia. A 16 year old boy got on Grindr and interacted with older guys looking to hook up with younger guys and then blackmailed them threatening to publicly out them as pedophiles.
One man they blackmailed committed suicide.
I have never checked out the smart phone hook up apps but this shows the danger that they can have.
Canberra Grindr extortion ring accused driven by a 'perverted sense of morality'