Security issue! Critical!
Mails are displayed as is in your page, this is ground for harvest for spam crawlers.
Encode the mails with JS or PHP GD in order to prevent it.
The most simple to be this (not 100% effective, but still somewhat effective):
At the beginning of the list
<script language="javascript">
var users=new Array;
var domains = new Array;
<?php
foreach($users as $u){
$l = explode("@",$u['email']);
?>
users.push('<?php echo $l[0];?>');
domains.push('<?php echo $l[1];?>');
<?php
}
?>
</script>
Within the cell that displays the email address:
<td>
<script language='javascript'>
if(users[<?php echo $row_nr;?>] != ""){
document.write(users[<?php echo $row_nr;?>] + "@" + domains[<?php echo $row_nr;?>]);
}else{
document.write(' ');
}
</script>
<noscript>Email protected</noscript>
</td>
