I disagree that 'everyone knew what Savile was up to'. Within the worlds in which he moved (TV, hospital charities, etc) many people were aware of rumours, but nothing concrete. Many people have said since that, if they'd had any proof, they would have spoken up, but they never did have firm evidence. Those who did know for sure - the victims - were afraid to speak, and indeed, what 'evidence' did they have, either? Savile was clever enough and powerful enough (and on occasion, threatening enough) to keep a lid on it all.
Yes, it's tricky, because we don't want witch hunts against the innocent - but there you have it, the danger of waiting for positive, actual proof - and ignoring what we might call the anecdotal evidence. If we haven't learnt a lesson from that saga, then I don't know what to say.