Instructions like this are vital in business, too. I worked for a large networking hardware company (which shall remain nameless) and I recall spreadsheets developed for customers which had summary graphs. If you clicked on the summary graph, however, you would be led to complex pricing and technical analysis that should have never been let out of the company. This is a serious issue that is a serious conduit for the release of classified information no matter who you work for.
See post 8.