class Employee
    {
        private string fullName;

        public Employee(string fullName)
        {
            this.fullName = fullName;
        }

        static void Main(string[] args)
        {
            Employee emp = new Employee("Mary");
            Console.WriteLine(emp.fullName);
            emp.fullName = "Anna";
            Console.WriteLine(emp.fullName);
        }
    }

Mary
Anna
Press any key to continue

_>А что теперь можно обращаться к private членам классов и изменять их?

_>    class Employee
_>    {
_>        private string fullName;

_>        public Employee(string fullName)
_>        {
_>            this.fullName = fullName;
_>        }

_>        static void Main(string[] args)
_>        {
_>            Employee emp = new Employee("Mary");
_>            Console.WriteLine(emp.fullName);
_>            emp.fullName = "Anna";
_>            Console.WriteLine(emp.fullName);
_>        }
_>    }
_>

_>Или я что-то не понял...

    class Employee
    {
        private string fullName;
    ...
    }

    class MyApp
    {
        static void Main(string[] args)
        {
            Employee emp = new Employee("Mary");
            Console.WriteLine(emp.fullName);
            emp.fullName = "Anna"; // будет ругаться
            Console.WriteLine(emp.fullName);
        }
    }
>