The problem is that nobody has to prove themselves innocent. You have to prove them guilty. It is very difficult to prove a negative, ie. something did not happen, it is more reliable to prove something did happen.
That's the exact type of crap SJWs eat up, especially with shit like "Believe all women" and such. In that situation, all that's needed is an accusation.
How about this: I now accuse you of being a pedo. Go ahead, prove your innocence.