JS copy To Clipboard (prevent coping/cutting programmatically)

gistfile1.txt

// Copies a string to the clipboard. Must be called from within an
// event handler such as click. May return false if it failed, but
// this is not always possible. Browser support for Chrome 43+,
// Firefox 42+, Safari 10+, Edge and IE 10+.
// IE: The clipboard feature may be disabled by an administrator. By
// default a prompt is shown the first time the clipboard is
// used (per session).
function copyToClipboard(text) {
    if (window.clipboardData && window.clipboardData.setData) {
        // IE specific code path to prevent textarea being shown while dialog is visible.
        return clipboardData.setData("Text", text); 

    } else if (document.queryCommandSupported && document.queryCommandSupported("copy")) {
        var textarea = document.createElement("textarea");
        textarea.textContent = text;
        textarea.style.position = "fixed";  // Prevent scrolling to bottom of page in MS Edge.
        document.body.appendChild(textarea);
        textarea.select();
        try {
            return document.execCommand("copy");  // Security exception may be thrown by some browsers.
        } catch (ex) {
            console.warn("Copy to clipboard failed.", ex);
            return false;
        } finally {
            document.body.removeChild(textarea);
        }
    }
}
var func = function(e) {
  // e.clipboardData is initially empty, but we can set it to the
  // data that we want copied onto the clipboard.
  e.clipboardData.setData('text/plain', 'copy or cut is disabled!');
  e.clipboardData.setData('text/html', '<b>copy or cut is disabled!</b>');

  // This is necessary to prevent the current document selection from
  // being written to the clipboard.
  e.preventDefault();
};
// Overwrite what is being copied to the clipboard.
document.addEventListener('copy', func);
document.addEventListener('cut', func);