C J Campbell wrote:
No one has been shot down by black helicopters or F-16s. Imagine the
fallout if someone were.

Not in the U.S. - yet. This incident happened in 2001 in Peru and the
CIA allegedly was involved:

http://findarticles.com/p/articles/m...18/ai_75089670
http://query.nytimes.com/gst/fullpag...gewanted=print

"Peru's air force denied April 23 that it did anything wrong in an
incident that led to the death of a missionary and her daughter when
their plane was shot down April 20 in the South American country. But
friends and relatives of the missionaries said they were fired on
without warning.

A pontoon-equipped single-engine Cessna carrying missionaries affiliated
with the Pennsylvania-based association of Baptists for World Evangelism
was forced to crash-land in the Amazon River after a Peruvian fighter
jet opened fire on the plane, which it mistakenly thought was
transporting illegal drugs. Missionary Veronica Bowers and her
seven-month-old daughter, Charity, were killed. Pilot Kevin Donaldson
underwent surgery after being seriously wounded in both legs in the
incident. Reportedly, the jet strafed the survivors as they clung to the
plane's burning wreckage in the river."

Here's a followup story some months later of the investigation findings:

http://transcripts.cnn.com/TRANSCRIP.../02/se.02.html