self-censor current page

darkpeak.js

function blacken() {
    var div = document.createElement('div');
    var opacity = 0;
    div.style.position = 'fixed';
    div.style.top = 0;
    div.style.bottom = 0;
    div.style.left = 0;
    div.style.right = 0;
    div.style.opacity = opacity;
    div.style.background = 'black';
    document.body.appendChild(div);
    var timer = setInterval(darken, 100);
    function darken() {
        opacity += 0.005;
        div.style.opacity = opacity;
        if (opacity >= 1) clearInterval(timer);
    }
}