Across the country this weekend, minor alerts brought major responses.
At New York's John F. Kennedy Airport, a suspicious package led to the closing of the American Airlines terminal.
And in Washington, D.C., a block in the city's Georgetown neighborhood was cordoned off for a suspicious object that was later blown up. It turned out to be a homeless man's backpack.
Buses were stopped and searched on the way to Reagan National airport outside the capitol, and cars were randomly pulled over for searches at Los Angeles International Airport.
With tensions high overseas, it's always a debate whether to increase security at home.
ABC News security consultant Jerry Hauer said, "The notion that every time something happens in London or somewhere else in the world means that we have to enhance security nationwide, you get this rollercoaster effect and eventually, people stop focusing on these enhanced threats."
The Department of Homeland Security has put additional air marshals on overseas flights, and bolstered plans for stepped up security over the Fourth of July. But, long lines and delays were the most immediate hazards to travelers.
At New York's LaGuardia Airport, passenger Roberta Podell said, "I'm not nervous at all and I understand if there are delays for security reasons — I can live with that."
Making the rounds of the Sunday talk shows, Homeland Security Secretary Michael Chertoff said there was no reason to raise the level of the national security alert, which is currently elevated.
On "This Week with George Stephanopoulos," Chertoff pointed out that the air travel alert has already been at orange, or high, for nearly a year.
"The threat level for aviation has been at orange since last August, when we had foiled the bombing plot involving airlines from the UK to the United States," Chertoff said. "But, we do not have any specific credible evidence that there's an attack focused on the United States at this point."