President Obama ordered heightened use of the watch list and screening.
Every time there is an incident anywhere, security gets ratcheted up everywhere. As a consequence, there have been some longer lines at O'Hare, but the impact is not nearly as much domestically as on international flights arriving in the U.S.
Everybody standing in line in Amsterdam was given pat-downs, according to passenger John Fogarty.
"Everybody. Everybody. Nobody walked by, trust me," Fogarty said.
Though the restrictions may soon be eased, passengers arriving from Europe had new rules in the last hour of their flights.
"We were not allowed to get up or use the restroom in the last hour," said Sandra Rainartz, who arrived from Frankfurt.
"Before landing, nothing on our lap, nothing on the seat next to you. You have to store everything above you. No bags, no phones, nothing," said Stephen Kollegger, who arrived from Frankfurt.
Those restrictions didn't apply to domestic flights, though passengers did experience longer lines and more visible security.
"You're going to see more pat-downs, probably going to get a closer look at hand luggage, and they're probably going to do more random searches of people," said DePaul University Prof. Thomas Mockaitis.
The critical question is why the would-be bomber was not more rigorously screened. He bought his ticket in cash, a one-way ticket, had no luggage for an international flight and was on a terror watch list. Some believe the U.S. watch list has become unmanageable.
"They should have a coordinated list, a better list for checking. So they can zip it right through," passenger Sue Wene said.
Watch list procedures will under go review and there will be likely debate anew on the use of full body scanners.
They're designed to pick up objects, nonmetallic, being hidden but they show the entire body and that's raised significant privacy questions.
Neither O'Hare nor Midway have the full body scanners.
They are in use at a couple dozen airports around the U.S, but as secondary options because the debate over privacy remains unresolved.
Schiphol Airport in Amsterdam does have them and now says it will require their use.