Index: services/userservice.php
===================================================================
--- services/userservice.php	(revision 4)
+++ services/userservice.php	(working copy)
@@ -364,6 +381,14 @@
         }
     }
 
+    function isReasonableUsername($name) {
+	$pattern = "(xyz|xxx|abc|123|poker|naked|nude|sex|porn|spam|texas|invoice)";
+	if (eregi($pattern, $name)) {
+		return false;
+	}
+	return true;
+    }
+
     function isValidEmail($email) {
         if (eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,6})$", $email)) {
             list($emailUser, $emailDomain) = split("@", $email);
Index: register.php
===================================================================
--- register.php	(revision 4)
+++ register.php	(working copy)
@@ -48,6 +51,10 @@
 		} elseif ($userservice->getUserByUsername($posteduser)) {
 			$tplVars['error'] = T_('This username already exists. Please make another choice.');
 		
+		// Check if username is reasonable
+		} elseif (!$userservice->isReasonableUsername($posteduser)) {
+			$tplVars['error'] = T_('I do not like this username. Please make another choice.');
+		
 		// Check that password is long enough
 		} elseif ($postedpass != '' && strlen($postedpass) < 6) {
 			$error = true;