I am surprised to read this. What kind of systems are these? How are they able to monitor if a private key is leaked or not. Its confusing to understand and it should be known to everyone so that I won't be making the mistake of leaking my private key by accident.
For example, whether it is phishing sites, or a software downloaded from play store, or any browser extension? What kind of monitor? & how does it recognize the gibberish code as pvt key anyways?
If I am not wrong, there are websites that have some private keys being shared or posted because I tried accessing one of it (bnb network) and I tried sending a very small amount of bnb to the wallet address that didn't even reach 1 dollar but once it was in the wallet ehen the bnb was transferred right away. Although I have seen it myself but I never knew what they did use or how they monitor the wallet but it is true that leaked private keys are being monitored and in btc, the same thing goes as well.