Let's say my social security number is "stolen", but I never need to take out new debt and don't use my credit score, have no intention of collecting social security as part of my retirement plan, and I instruct my current bank and investment firms to only allow operations on the basis of username / password, meaning my SSN cannot be used to convince my bank and investment brokers to hand over control of my account to someone else. House is paid for. I'm super rich with cash, liquid assets, and stocks in accounts that only I can access.
What's the worst that could possibly happen? Why should I care? I'm not using it and I can't be held responsible for any of the fraud committed.