In the early 2000s after 9/11 there was a guy doing public surveillance tours around New York City using "photocopies of hand-drawn maps". NY Times archive.org

In the early 2000s after 9/11 there was a guy doing public surveillance tours around New York City using "photocopies of hand-drawn maps". NY Times archive.org https://web.archive.org/web/20100317184609/https://www.nytimes.com/2004/01/17/nyregion/watching-big-brother-on-this-tour-hidden-cameras-are-hidden-no-more.html https://web.archive.org/web/20100317184609/https://www.nytim...