We already have a question on whether you can attend a job interview or look for work while in the US on a tourist visa. (Actually it's unresolved with two possibly conflicting answers and no solid reference).
And we have a more recent question asking about looking for work while on a business visitor visa. (Currently on hold as a duplicate of the former but maybe it's different).
But what about for people who don't require a visa to enter the US but can visit on the Visa Waiver Program? Are such people allowed to job hunt in America?