Frequency Jamming

Picture credit: http://www.faa.gov
Like handheld lasers pointed at airliners to (presumably) blind pilots, this Washington Times report is somewhat ominous:

...Shortly before touching down in Charlotte, the pilot announced to passengers that the landing was being delayed because somebody was "jamming" the plane's communications with the control tower. "We have a jamming problem," the lawyer, who asks not to be identified, paraphrased the pilot. "We've gotten word from the tower that our radio frequencies are being jammed." Then these words: The problem could "involve national security." ..."Unless you find the source, you're not sure if it's inadvertent or on purpose. As you know from reporting on the lasers [being beamed at pilots from the ground], laser incidents go back 10 years. But it wasn't until the September 11th attacks that we have to look at everything through national security lines now."

Washington Times: Jamming