Registered users viewing numbers is one thing but there were numerous bots, from many countries, that were continually scraping data. So I used the ignore data option in the admin section for the SSN custom event. Unfortunately this hides the information from everyone including family members. So I created a mod that hides Social Security Numbers unless a user logs in. When the mod is installed, the default option requires users log in and have View Information for Private Individuals permission to view Social Security Numbers. If the option is set to 1 all users that log in can view Social Security Numbers.
If you have a private site requiring everyone to login, you probably have no use for this mod. If you have a public/private site or you want to use permissions to access the SSN event, you might find the mod useful.
Revision 4 - Removes Social Security Number search option from advanced searches.
The mod was tested on TNG versions 12.1, 12.2 and 12.3.