Current User Capabilities

Heya,

I am looking at putting together a query for posts that the current user has access to. So my thought process was that first I’d have to establish current user’s capabilities then build a WP_Query off of that. However I seem to be stuck at the first hurdle with $user->__get(‘capabilities’) returning NULL.

Is there any reason this would be happening/better way to query the posts.

$user_id = get_current_user_id();
$user = new Groups_User($user_id);
$groups = $user->__get('groups');

// Get Current user capabilities
$caps = $user->__get('capabilities');

http://wordpress.org/extend/plugins/groups/