JSFiddle - React, Tailwind, and code Playground
HTML
<div class="entryFooter">Posted by mjroodt at 24/10/2011 11:48<a href="/BlogPage.aspxid=20396&blogid=58906">Comments (1)</a></div>
<div class="entryFooter">Posted by mjroodt at 27/10/2011 13:33<a href="/BlogPage.aspx?id=12396&blogid=58945">Comments (2)</a></div>
<div class="entryFooter">Posted by mjroodt at 27/10/2011 15:59<a href="/BlogPage.aspx?id=14396&blogid=59963">Comments (7)</a></div>
JavaScript
$('div').each(function () {
var text = $(this).text(),
name = text.match(/Posted by (.+) at .+/)[1]
$(this).text(text.replace(name, 'anon'))
});