Horrible though this is, it's (bizarrely) better than the pre-ESTA alternative. My brother was denied entry to the US in 2003 while traveling on a visa waiver. At this point he was detained (without access to counsel) until a suitable outbound flight was available, and deported. The red stamp in his passport renders him ineligible to apply for an entry visa until 2018. This is all on the discretion of one immigration official, with no recourse for appeal. The justification is that when you sign the visa waiver, you agree to all this.

Edit: my brother is not entirely innocent in all this, but knowing before you fly is an improvement