Many Customs administrations around the world take the view that the public is an important source of intelligence.
For instance, read about New Zealand’s Coast-watch program through the link provided.
https://learn.csu.edu.au/content/enforced/32898-S-
CUS411 202475/CUS411%20-%20Documents/Coastwatch.pdf
* note : Includes link file with portable files.( Coastwatch)