Imagine if he DIDN'T turn in the guy and the perv ended up molesting some kids.
Based on that argument, should we report every man who buys porn magazines, because he may rape beautiful women?
Should we arrest every person who laughs at racist jokes (even sick racist jokes), because they may harm someone of a different race?
Does anyone have any solid evidence that everyone who looks at child pornography will molest kids? (It seems believable, but is it really true.)
I want to be sure that we are not stepping into the realm of "thought policing" rather than policing criminal acts.