Romanian-born American poet and commentator Andrei Codrescu wrote in The Muse Is Always Half-Dressed in New Orleans: And Other Essays (1993):
 
“Tourists are terrorists with cameras, while terrorists are tourists with guns. Tourism is the civilian aspect of imperialism. After the natives have been pacified by force of arms, we finish the job with the cameras. It’s no coincidence that both activities are called ‘shooting.’ It’s hard for me to look at old National Geographics without feeling an anguished nausea. There they are, on display, the dead freaks of worlds we have destroyed. They’ve left forms behind for the use of the fashion industry.”
 
“Tourists are terrorists with cameras; terrorists are tourists with guns” has been widely cited.
 
   
Wikipedia: Andrei Codrescu
Andrei Codrescu (born December 20, 1946, Sibiu, Romania) is a Romanian-born American poet, novelist, essayist, screenwriter, and commentator for National Public Radio. He was Mac Curdy Distinguished Professor of English at Louisiana State University from 1984 until his retirement in 2009.
   
Google Books
The Muse Is Always Half-Dressed in New Orleans: And Other Essays
By Andrei Codrescu
New York, NY: St. Martin’s Press
1993
Pg. 10:
Well, at least, one might say, tourists aren’t killing anybody for a picture.
 
Isthat the difference between tourism and terrorism? Tourists are terrorists with cameras, while terrorists are tourists with guns. Tourism is the civilian aspect of imperialism. After the natives have been pacified by force of arms, we finish the job with the cameras. It’s no coincidence that both activities are called “shooting.” It’s hard for me to look at old National Geographics without feeling an anguished nausea. There they are, on display, the dead freaks of worlds we have destroyed. They’ve left forms behind for the use of the fashion industry.
   
Google Groups: rec.arts.sf.written
Moran: _The Last Dancer_
Bryant Durrell
11/7/93
(...)
“Tourists are terrorists with cameras; terrorists are tourists with guns.”
—Andrei Codresque
 
Google Books
Road Scholar:
Coast to Coast Late in the Century
By Andrei Codrescu
New York, NY: Hyperion
1993
Pg. 33:
Tourists are terrorists with cameras. Terrorists are tourists with guns.
 
Google Books
Restlessness:
A Novel
By Aritha Van Herk
Red Deer, Alberta: Red Deer College Press
1998
Pg. 98:
So only spies and those who document atrocities should use cameras?” ‘Yes, in the hands of the ordinary person, they are an affront. Who was it said, ‘Tourists are terrorists with cameras, while terrorists are tourists with guns’? They both shoot what they can’t tame.”
 
Google Books
Quotations on Terrorism
By Harry Kawilarang
Victoria, BC: Trafford
2004
Pg. 421:
Tourists are terrorists with cameras. Terrorists are tourists with guns.
Anon
   
DSLRphoto.com
Photography Quote of the Day - Anonymous - December 16
2013-12-16 14:00
“Tourists are terrorists with cameras. Terrorists are tourists with guns.” - Anonymous