The reaction to Trump’s executive order has been enormous, so it’s useful to remember that the scale of what happened over the weekend was not, per this report:
A Department of Homeland Security official said the travel ban affected 375 travelers, 173 of whom were denied entry to the country prior to boarding flights headed to the U.S. The official said 109 people who were in transit to the U.S. were denied entry and 81 people were granted waivers because of their legal permanent resident or special immigrant visa status.
This USA Today report has some more detail:
A senior Homeland Security official, who spoke on condition of anonymity to provide an operational update on Trump’s executive order, said the department quickly overhauled its screening procedures after Trump signed the order Friday. The department issued new guidance to its Customs and Border Protection officers in the field and adjusted its computerized targeting system to identify people who are barred entry through the executive order.