Well, you have to keep in mind that usually this power is used to force people to testify in serious crimes. I mean, this is how you get drug rings and other kind of conspiracies. It's really pretty standard throughout criminal prosecutions. It's also common in civil actions - one guy was jailed for contempt because he refused to reveal his assets to his wife in a divorce action. Jail and fines are really the only way to get people to comply with a court order.