Thinking about locking 1 BTC in my nsec as a proof of key safety. If somebody gets my key, they can steal the 1BTC. And if they do, I will know my key has leaked.

On Nostr, unless you monitor your own posts VERY closely, you never know if your key has leaked or not. That creates lots of liabilities for businesses and some risks for users. Adding a value that is appropriate to the size of the account could work as attack notifier. And business might even be able to insure that amount with cyber insurance. 🤔