I know of a bunch of cases where Iranian Swedes got ESTAs revoked, and the stream of them coming into the US Embassy in Stockholm has made the waiting room's visa applicants have quite a different look than during the weeks/months/years prior to this wave of "VWP enhancements".

Most Swedes who get revoked ESTAs do get notification of revocation; but some of the notifications of ESTA revocation don't take place until within days, hours or even minutes of scheduled flight departure that has been booked. And sometimes the revocations even take place after check-in but before flight has departed. I've not yet been told of an Iranian Swede having an ESTA revoked in-flight, but I wouldn't be surprised if it happened/happens. Meanwhile, the irony is that personal secretary to POTUS is an Iranian-American with EU citizen relatives who are also now hit by this "enhancement". Oh the irony, given she landed the position as a result of her work for the National Security Council at the White House.