Avatar Blacklist Userscript for Identica

I'm on a microblogging site called Identica, and there are a lot of interesting people in the various groups there. However, sometimes while I find a user's content interesting, I don't like looking at their avatar for whatever reason. I'm not going to name names, but to get around this, I wrote this userscript to display the default avatar for select users.

// ==UserScript==
// @match http://identi.ca/*
// ==/UserScript==

(function() {
    var onLoadCallback = function() {
        var blacklist = {
          // put the usernames of the people whose avatars you
      // would like to block as the keys in this object; the
      // values can be anything
        };
        var replacement = 'http://theme.identi.ca/1.0.0/neo/default-avatar-profile.png';

        var handleImage = function() {
            var parentTitle = $(this).parent().attr('title');
            var alt         = $(this).attr('alt');

            if(alt in blacklist || parentTitle in blacklist) {
                this.src = replacement;
            }
        };

        $('img.avatar').each(function(_, element) {
            handleImage.call(element);
        });
        var script = document.createElement('script');
        script.src = 'http://brandonaaron.net/javascripts/plugins/livequery.js'
        $(script).load(function() {
            $('img.avatar').livequery(function() {
                handleImage.call(this);
            });
        });
        document.body.appendChild(script)
    };

    var callback = function() {
        var script = document.createElement('script');
        script.textContent = "(" + onLoadCallback.toString() + ")()";
        document.body.appendChild(script);
    };

    if(document.readyState == 'complete') {
        callback();
    } else {
        document.body.onload = callback;
    }
})();