It isn't really about mandated reporting completely -- it's about reporting. Mandated reporting can make a therapist anxious and cause them to report someone even when their judgment is that there is no need to report. But they can also make a report just because they personally think it's the right thing to do. I think Matthew's questions address this, as he's asking about when they would report, not when they would make a mandated report. There's a longstanding "duty to warn". If a client says, "I'm going to kill Mr. X this weekend" then the therapist has a duty to warn Mr. X. Hopefully that is considered pretty narrowly.

I do think email could skew the answers considerably. No one wants to go on record as saying they would breach a patient's confidentiality unnecessarily -- a serious breach of professional ethics. But in the moment, with a particular situation, it might be different.

What people have reported in the Virtuous Pedophiles group (and I think B4U-ACT too) is sudden termination of the therapeutic relationship when attraction to children is mentioned. Sometimes just a call between sessions to say they can't meet again, with no referral to any other therapist. It could be simple prejudice, or simple preference -- one therapist emailed me saying that therapists get to decide who they want to spend their days talking to, something a lot of us would like. It also could be a quick way out between a rock and a hard place -- the mandate of patient confidentiality and the mandate of potential abuse reporting. Now, terminating the relationship is not going to ruin a pedophile's life, but if you feel it's a great cause for shame (which many do) it's going to be very demoralizing to get the courage to tell someone and then have them tell you to get lost.

I blogged on this basic subject:
http://celibatepedos.blogspot.com/2014/07/keep-kids-safer-get-rid-of-mandated.html

Saying "almost all therapists would not report unless..." is OK if you mean that 9,999 out of 10,000 would not report. If it means that 4 out of 5 would not report, that could reasonably be considered an unacceptable risk.