Because there's a lot of garbage on there. You can also set your own filters!

hf.unclutterbanspage.user.js

// ==UserScript==
// @name         HF Unclutter bans.php page
// @namespace    HF Unclutter bans.php page
// @version      0.4
// @description  Because there's a lot of garbage on there. You can also set your own filters!
// @author       Cammy
// @match        *hackforums.net/bans.php
// @require     http://ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js
// ==/UserScript==

var filters = [
    "violation earns an automatic 3-day ban.",
    "vacation",
    "https://hackforums.net/member.php?",
    "spam"
];

var highlights = [
    "close",
    "come back",
    "join"
];

$('tr').each(function() {
    try
    {
        var trow = $(this).find(".trow2")[0];

        for (var ii = 0, highlightLen = highlights.length; ii < highlightLen; ii++) {
            if($(trow).html().toLowerCase().indexOf(highlights[ii].toLowerCase()) !== -1)
            {
                $(trow).css("background", "#403333").addClass("highlighted");
            }
        }


        for (var i = 0, filterLen = filters.length; i < filterLen; i++) {
            if($(trow).html().toLowerCase().indexOf(filters[i].toLowerCase()) !== -1 && $(trow).hasClass("highlighted") === false)
            {
                $(trow).parent().remove();
            }
        }

    }
    catch(err){}

});