diff --git a/actions/finishopenidlogin.php b/actions/finishopenidlogin.php
index 27e5057ec1..fe9894e52b 100644
--- a/actions/finishopenidlogin.php
+++ b/actions/finishopenidlogin.php
@@ -167,6 +167,11 @@ class FinishopenidloginAction extends Action {
 			$this->show_form(_t('Nickname must have only letters and numbers and no spaces.'));
 			return;
 		}
+
+		if (!User::allowed_nickname($nickname)) {
+			$this->show_form(_t('Nickname not allowed.'));
+			return;
+		}
 		
 		if (User::staticGet('nickname', $nickname)) {
 			$this->show_form(_t('Nickname already in use. Try another one.'));
@@ -338,6 +343,9 @@ class FinishopenidloginAction extends Action {
 										  'format' => VALIDATE_NUM . VALIDATE_ALPHA_LOWER))) {
 			return false;
 		}
+		if (!User::allowed_nickname($str)) {
+			return false;
+		}
 		if (User::staticGet('nickname', $str)) {
 			return false;
 		}
diff --git a/actions/profilesettings.php b/actions/profilesettings.php
index 6764ad288f..b6e24c7299 100644
--- a/actions/profilesettings.php
+++ b/actions/profilesettings.php
@@ -88,6 +88,8 @@ class ProfilesettingsAction extends SettingsAction {
 													  'format' => VALIDATE_NUM . VALIDATE_ALPHA_LOWER))) {
 			$this->show_form(_t('Nickname must have only letters and numbers and no spaces.'));
 			return;
+		} else if (!User::allowed_nickname($nickname)) {
+			$this->show_form(_t('Not a valid nickname.'));
 		} else if (!is_null($homepage) && (strlen($homepage) > 0) &&
 				   !Validate::uri($homepage, array('allowed_schemes' => array('http', 'https')))) {
 			$this->show_form(_t('Homepage is not a valid URL.'));
diff --git a/actions/register.php b/actions/register.php
index 31c8fea70f..16e80ef171 100644
--- a/actions/register.php
+++ b/actions/register.php
@@ -57,6 +57,8 @@ class RegisterAction extends Action {
 			$this->show_form(_t('Nickname must have only lowercase letters and numbers and no spaces.'));
 		} else if ($this->nickname_exists($nickname)) {
 			$this->show_form(_t('Nickname already exists.'));
+		} else if (!User::allowed_nickname($nickname)) {
+			$this->show_form(_t('Not a valid nickname.'));
 		} else if ($this->email_exists($email)) {
 			$this->show_form(_t('Email address already exists.'));
 		} else if ($password != $confirm) {
diff --git a/classes/User.php b/classes/User.php
index 0e7fd54474..e735457f9d 100644
--- a/classes/User.php
+++ b/classes/User.php
@@ -83,4 +83,12 @@ class User extends DB_DataObject
 		  ' WHERE id = ' . $this->id;
 		return $this->query($qry);
 	}
+	
+	function allowed_nickname($nickname) {
+		# XXX: should already be validated for size, content, etc.
+		static $blacklist = array('rss', 'xrds', 'doc', 'main',
+								  'settings', 'notice', 'user');
+		$merged = array_merge($blacklist, common_config('nickname', 'blacklist'));
+		return !in_array($nickname, $merged);
+	}
 }
diff --git a/config.php.sample b/config.php.sample
index bfd1da8ce2..8253bdeed6 100644
--- a/config.php.sample
+++ b/config.php.sample
@@ -33,3 +33,6 @@ $config['db']['database'] = 'mysql://laconica:microblog@localhost/laconica';
 
 #session_set_cookie_params(0, '/'. $config['site']['path'] .'/');
 
+#Standard fancy-url clashes prevented by not allowing nicknames on a blacklist
+#Add your own here. Note: empty array by default
+#$config['nickname']['blacklist'][] = 'scobleizer';
diff --git a/lib/common.php b/lib/common.php
index 83b56dcee5..2853c56e3d 100644
--- a/lib/common.php
+++ b/lib/common.php
@@ -54,7 +54,9 @@ $config =
 			  'image' => 'http://i.creativecommons.org/l/by/3.0/88x31.png'),
 		'mail' =>
 		array('backend' => 'mail',
-			  'params' => NULL)
+			  'params' => NULL),
+		'nickname' =>
+		array('blacklist' => array())
 		);
 
 $config['db'] = &PEAR::getStaticProperty('DB_DataObject','options');