Just to put it out there before I say what I have to say, I'm a Modern Orthodox Jew myself.
These terrible crimes have some parallels with what is going on in Rochdale, and are also different in some ways. This abuse stems from the fact that in both communities sex is something that is pretty much never discussed, and sex is seen as something that children and young adults are not to find out about until they are married (usually in an arranged marriage, in both cases). This philosophy is not compatible with the information age, since even the most censored young Orthodox Jewish, or strict Muslim kids can find out about this whole other world quite easily.
This can lead to members of both communities developing some pretty weird views about what is acceptable and, as we have seen, can have some disastrous consequences.
This should not be used as an excuse for hate crimes against either community. Rather, we should campaign for greater openness and at least some rudimentary sex-ed in these communities.
As for the refusal of some leaders to hand these criminals over, this comes from a deep distrust of non-Jewish authority within ultra-Orthodox circles. Ultra-Orthodox Jews devote their lives to following what their Rabbis tell them, so attitudes change very slowly. The attitude shown by Ultra-Orthodox Jews towards non-Jewish authority is probably a remnant of the Holocaust, or even earlier, with the pogroms etc. I'm not saying that this attitude is acceptable, I am just explaining it.