Why can JS scripts conflict?

Question

JavaScript

Hello. In the Chrome extension, the code is launched using window.onload ,
followed by replacing words from arrays with stars.

But when the extension is enabled, the forms on several sites do not work - for example, online.sberbank.ru.

Answer 1

Use https://developer.mozilla.org/ru/docs/Web/API/Even...

Answer 2

On the websites of banks, because the client is not serious, everything breaks down, and then suddenly a scammer with his cool hacker scripts.

Answer 3

If you change the characters in the value of some input to asterisks, then this value may not pass validation, for example. But this is a pitchfork in the water, you have to look at exactly how "forms do not work"