Never ever do this on your website

titleChanger.js

(function () {
    var titleValue = document.title;
    var hidden = "hidden";

    function onchange() {
        document.title = document.hidden ? "Pssst! We’re Still Here…" : titleValue;
    }

    if (hidden in document) {
        document.addEventListener("visibilitychange", onchange, false);
    }
    else if ((hidden = "mozHidden") in document) {
        document.addEventListener("mozvisibilitychange", onchange, false);
    }
    else if ((hidden = "webkitHidden") in document) {
        document.addEventListener("webkitvisibilitychange", onchange, false);
    }
    else if ((hidden = "msHidden") in document) {
        document.addEventListener("msvisibilitychange", onchange, false);
    }
    // IE 9 and lower:
    else if ("onfocusin" in document) {
        document.onfocusin = document.onfocusout = onchange;
    }
    else
        window.onpageshow = window.onpagehide
            = window.onfocus = window.onblur = onchange;
})();

Copied from Sarova hotel engine.
https://bookings.sarova.com/rates-room

When you go away from the Sarova tab, the <title> changes to Pssst! We’re Still Here…. And instead of having a clear title, you get this weird shit.