"Chilling effect" has always been a profound term for me, because I imagine the "cold" (numbness really) sensation a human body often senses when something truly awful (disembowlment/dismemberment) occurs. The body's way of protecting itself is to go "cold", and in many ways that's exactly the effect taking place here, as well.
There's also an undeniable part of this conversation that rarely gets addressed simultaneously, and I'd like to see it sussed out more in concert; what about the folks who are doing Evil in these private channels? It's unacceptable to me that TOR gets used for child pornography, and it's unacceptable to me that my government finds out I'm gay before I come out to my family.
I don't want to provide those who would do Evil any safety or quarter. I also want to give people a powerful shield to protect themselves against judgement and persecution from the public and sometimes the law.
We should talk about achieving both of these goals, but we generally don't.
Seatbelts, airbags, traffic lights, food safety, drug safety, pollution control, national defense and many more benefit pedophiles just as they protect good people.