SQL Server column level security
Column level security does not work that way. I'm aware of no mechanism to globally deny access to a certain column for a given user. The GRANT/DENY only works on specific statements like SELECT, UPDATE and so on in combination with a given object.

So in your case, if you removed access on SELECT for column X on table Y the user can still happily execute "select *" views on that table because the view is a different object and is unaffected by this security setting!

The good news is that you can use column permissions on views also. It works just the same as with tables, but you have to set the permission on every view that includes the SSN column.