Tactics have included plane hijackings, stone throwing, stabbing, shootings, and bombings.
In the space of a few days, there have been half a dozen plane hijackings, people trying to go to Antarctica or Nepal.
His group, the Popular Front for the Liberation of Palestine, is best known for plane hijackings in the 1960's and 70's.
The warning identified transit systems as the most likely target, but also pointed to public gathering places and commercial buildings and spoke of vehicle bombs and plane hijackings.
The plane hijackings shook a lot of people's confidence in air travel.
Before the plane hijackings on Sept. 11, 2001, only about 5 percent of checked baggage was screened.
Hot pants, plane hijackings, psychedelic art.
He sees school shootings, plane hijackings, and other such events as a result of prohibitions on self-defense.
For plane hijackings within the "special jurisdiction of the United States, the lead agency was the Federal Aviation Administration.
Most events that receive extensive daytime coverage are unexpected: plane hijackings, the explosion of the space shuttle and the assassination attempt on President Reagan, for examples.