Did you actually read the emails ? They were just friendly - nothing about sex and nothing personal except the request for the boy's picture. The page oversight committee was informed by the boy's parents, Hastert was then informed, and responded by telling Foley to stay away from the pages.
What else should he have done ? Investigate what ? There was no "there" there. Even the police can do no more if a crime has not been committed. The FBI was shown the emails and didn't investigate because there was no crime. Various news organizations declined to publish the story last year because there was nothing to it.
Are you saying Hastert should have felt more powerful than the FBI and done more ? He should have been all over what ?
If you have no specifics, don't throw mud just for the sake of piling on.