Stovepiping is a term of art in intelligence cycle management and intelligence analysis, which prevents proper analysis by preventing objective analysts from drawing conclusions based on all relevant data. It has acquired a broader meaning of manipulating information to prevent cross-checking that might not support a prejudgment.
Intelligence term of art
The traditional meaning keeps the output of different collection systems separated from one another. It prevents one discipline from cross-checking another. In the Second World War, both sides doubled clandestine agents and used them to send disinformation back to their own countries. While the content of the clandestine human-source intelligence (HUMINT) they sent might seem reasonable, direction finding, a discipline of signals intelligence (SIGINT) might have shown they were transmitting from Gestapo or British MI5 headquarters. Measurement and signature intelligence (MASINT) on the style of their radio procedure could have indicated that an impostor, or perhaps the real agent but under duress, was sending.
When first put under a loosely common management in the National Reconnaissance Office, the extremely expensive U.S. intelligence satellite programs suffered from stovepiping. The three major programs were organized by the military service that created the satellite program, rather than designing around a specific kind of information needed by each of the services and the Central Intelligence Agency.
Questions have been raised about the true utility of compartmented security and its contribution to stovepiping.  CIA, for example, mentioned that it was difficult for their analysts to get adequately detailed signals intelligence, and that the State Department, at the time, had minimal access to imagery intelligence (TALENT/KEYHOLE compartment)
Manipulation of intelligence
Second, a newer usage of stovepiping is bypassing the regular analysis of raw intelligence, and sending only raw intelligence that supports a particular position to the highest national leadership. Specifically, allegations were made that a large part of the justification from the U.S. invasion of Iraq, in 2003, came from the Office of Special Plans, a new office in the Department of Defense, under Douglas Feith, which effectively bypassed the intelligence review process and reported to Dick Cheney. Vice Presidential counsel Scooter Libby, however, claimed this was ridiculous, according to Bob Woodward. Woodward said Libby considered the office as two people who summarized sensitive intelligence for him, which was not given to the President or Vice President. Libby also said it was not a special channel for Ahmed Chalabi, whose information went to the CIA. 
- Masterman, J. C. (1972). The Double-Cross System in the War of 1939–1945. Yale University Press.
- Critique of the Codeword Compartment in the CIA, Center for the Study of Intelligence, Central Intelligence Agency, March 1977
- Katzman, Kenneth (August 15, 2008), Al Qaeda in Iraq: Assessment and Outside Links, Order Code RL32217, p. CRS-4
- Barry, Tom (February 12, 2004), Decentralizing U.S. Intelligence: Office of Special Plans, IRC Right Web
- Bob Woodward (2004), Plan of Attack, Simon & Schuster, ISBN 074325547X, pp. 288-289