"Allow Deletion of Running Applications" Option I needed to delete/uninstall an application that was running. It was screen saver app that ran over the regular screen saver, and I hated it. I downloaded it from the App Store, and do not suspect malware. It was just an awful, inexpensive app. When I tried to delete/uninstall it, I got a warning message that said I could not delete a running program. But it also gave me a link to where I could over-ride that, I think, within System Preferences. I clicked a checkbox that would "allow deletion of running applications." After checking that box, I was able to delete the offending application. 

I would like to go back to that setting and uncheck "allow deletion of running applications," but I can't find it in any of the System Preferences or other Utilities. A quick internet search revealed nothing. Maybe I'm using the wrong terms?

Is anyone aware of this setting and where it might be located?

Macbook Pro, OSX 10.11.5
The answer turned out to be something silly. I was using an app called "AppCleaner" to uninstall the application in question. The option to "Protect Running Apps" was actually in AppCleaner, not in the Mac OS itself. In order to delete the running application, I had to uncheck "Protect Running Apps." I was able to locate the Preferences within AppCleaner and re-check "Protect Running Apps."