Security Through Obscurity(STO) is well known in the Information & Technology (IT) industry but it is also common in the safe, vault, and security business.
In the IT industry it is the belief that a system of any sort can be secure so long as nobody outside of its implementation group is allowed to find out anything about its internal mechanisms. Hiding account passwords in binary files or scripts with the presumption that "nobody will ever find it" is a common case of STO. Many home owners have a similar belief that hiding their valuable items in their favorite hiding spots will prevent any burglar's from finding them.
Any intruder that enters a home with enough time will most likely find anything of value so, "Security Through Obscurity" is not the smartest way to think about security. Keeping your items safe from theft can be a sensitive issue. A good example of this is shown on "It Takes A Thief" where they have people volunteer to let a burglar break into their home and see how well their home is secured against theft.