Sony has introduced 2-Step verification for PlayStation Network accounts.
As with Steam, Battle.net, Xbox Live, Google and many other services, once the user signs in with their PSN ID, a verification code will be sent to the account holder via text.
One the code is sent, the user will need to enter said code in order to continue the sign in process.
The new security feature is optional, so it’s not being forced on PSN users. It’s a smart choice, however, for those who save their credit or debit card information on the service.
More information and instructions on how to activate 2-Step verification is posted above through the link.