Food Lion v. ABC (1996) -
http://www.cato.org/pub_display.php?pub_id=6090 (ABC goes undercover at Food Lion, reveals some badness and gets sued and loses)
WDAF-TV v McCASKILL (1996) -
http://www.law.umkc.edu/faculty/projects/ftrials/communications/WDAF-TV.htm... (man videotapes a murder and sells the tape to WDAF, the police seize the tape after the station refuses to provide a copy - look for section II which briefly describes the Privacy Protection Act)
More: US Code -
http://www.law.cornell.edu/uscode/42/2000aa.html (Searches and seizures by government officers and employees in connection with investigation or prosecution of criminal offenses)
More of the same:
http://uscode.house.gov/download/pls/42C21A.txt
The law makes provisions for videotaping someone selling, receiving, getting info about classified docs, defense secrets, etc., kiddie porn, and if there is an imminent danger and seizure will prevent a death. Part b specifically mentions it is illegal for law enforcement to seize documentary materials unless the person holding the material is believed to have committed a crime(s).
From the case of WDAF-TV v McCASKILL, "We find no ambiguity in the Privacy Protection Act. The Act presents a straightforward statutory scheme for protecting those engaged in information dissemination from government intrusion by prohibiting searches and seizures of documentary materials except where government officials have a reasonable belief that a statutory exception applies..." Statutory exceptions are:
(1) there is probable cause to believe that the person possessing such materials has committed or is committing the criminal offense to which the materials relate ...
(2) there is reason to believe that the immediate seizure of such materials is necessary to prevent the death of, or serious bodily injury to, a human being;
(3) there is reason to believe that the giving of notice pursuant to a subpena duces tecum would result in the destruction, alteration, or concealment of such materials...
The last part means they think you're gonna destroy or alter the material when you get a subpoena.
Long story short, you are probably okay to videotape people smoking pot for a documentary, but talk to a lawyer if you're not sure.
This is random, but I once was looking over a used video camera. There was a tape in it. Great, I thought, I'll test the tape to see if it works. I hit play and I saw footage of some people at a party with large piles of pot in front of them and people walking around with guns. Weighing my options quickly, I decided to pass on the camera and showed the seller the tape (he said he bought the camera from someone else). He quickly removed the tape and, turning bright pink, threw it away. ;)
Jonathan Ziegler
http://www.electrictiger.com/
520-360-8293