NY Times article
here.

Quadcopters. RC's.

Technology is available to jam the signals of an approaching
drone, Mr. Hearing said, which could cause the drone either to fall to the
ground or to return to its user. Such technology, much of it made in China, is
illegal for consumers and others to use, he said. Even more sophisticated
jammers could allow those protecting the White House to take control of the
drone from a user.