Edit in JSFiddle

var spamlist=[
 'http://www.blogger.com/profile/12345678',
 'http://namablog.blogspot.com/',
 'Alamat URL pengomentar ke-3'
];
for(var v=0; v<spamlist.length; v=v+1){
 $("a[href='"+spamlist[v]+"']").each(function(){
 $(this).closest(".comment-block").find(".comment-content")
 .replaceWith("<div class='comment-content' style='color:red'>Anda telah di banned! Silahkan tinggalkan blog ini!</div>"),
     $(this).replaceWith("<span style='color:red'>BANNED USER!</span>");
 })
}
<div id='comment-holder'>
    <ol>
        <li class='comment-block'><a href='http://www.blogger.com/profile/12345678'>Jojon</a>
            <p class='comment-content'>lorem ipsum dolor sit amet, amit-amit jabang bayi, bayi-bayi anak bang amit, bang amit orang nya elit.</p></li>
        <li class='comment-block'> <a href='http://www.blogger.com/profile/6789101112'>Cahyono</a>
            <p class='comment-content'>lorem ipsum dolor sit amet, amit-amit jabang bayi, bayi-bayi anak bang amit, bang amit orang nya elit.</p></li>
         <li class='comment-block'> <a href='http://namablog.blogspot.com/'>Nama Blog</a>
            <p class='comment-content'>lorem ipsum dolor sit amet, amit-amit jabang bayi, bayi-bayi anak bang amit, bang amit orang nya elit.</p></li>
    </ol>
</div>
body {padding:20px;}

.comment-content {
    border:1px solid black;
    padding:10px 15px;
    margin:0 0 10px;
}