JSFiddle - React, Tailwind, and code Playground

HTML

<script>
    // Muahahahaha!! That will show them hackors.
    window.alert = function(){};
    Window.prototype.alert = window.alert;
</script>

JavaScript

var msg = "your hacked. all you're alert are belong to us. lol.";

var frame = document.createElement('iframe');
document.body.appendChild(frame);
alert = frame.contentWindow.alert.bind(window);
document.body.removeChild(frame);

alert(msg);