Index: bp-core/bp-core-avatars.php
===================================================================
--- bp-core/bp-core-avatars.php	(revision 3424)
+++ bp-core/bp-core-avatars.php	(working copy)
@@ -207,7 +207,7 @@
 	// If no avatars could be found, try to display a gravatar
 
 	// Skips gravatar check if $no_grav is passed
-	if ( !$no_grav ) {
+	if ( ! apply_filters( 'bp_core_fetch_avatar_no_grav', $no_grav ) ) {
 
 		// Set gravatar size
 		if ( $width )
@@ -253,7 +253,11 @@
 			return apply_filters( 'bp_core_fetch_avatar_url', $gravatar );
 
 	} else {
-		return apply_filters( 'bp_core_fetch_avatar', false, $params, $item_id, $avatar_dir, $css_id, $html_width, $html_height, $avatar_folder_url, $avatar_folder_dir );
+		// No avatar was found
+		// Allow filtering based on the object (user/group/blog etc)
+		$default_avatar_location = apply_filters( "bp_core_default_avatar-$object", BP_PLUGIN_URL . '/bp-core/images/mystery-man.jpg', $params ); 
+		
+		return apply_filters( 'bp_core_fetch_avatar', '<img src="' . $default_avatar_location . '" alt="' . $alt . '" class="' . $class . '"' . $css_id . $html_width . $html_height . ' />', $params, $item_id, $avatar_dir, $css_id, $html_width, $html_height, $avatar_folder_url, $avatar_folder_dir );
 	}
 }