MSDN example here reads character by character in order to prepare secure string. which is possible in console or desktop applications. I do not see any direct way to read user password character by character in case of pure asp.net. Whatever technique I use, I end up storing password into some kind of string or make use of TextBox.Text which internally returns String. SecureString prevents revelation of information to the hacker. In case of asp.net, If hacker who gains access to memory can definitely read textbox.text and finds out the information. Moreover, Web application is deployed on server and server will be highly secured. Which definitely prevent hacker's direct access to memory.
So, Is SecureString really usefull in asp.net?