Some changes have been made to how the tracker works. When uploading a torrent there is now an additional 'Tracking type' option. If this is set to 'semi-private' then that torrent can be downloaded by anyone without a passkey, ie. non-members.
The idea is to give artists the choice of either sharing their work solely with the Panda.cd community or to use the tracker to reach a wider audience. For registered users such torrents are clearly labeled on the browse page as [Semi-private] and all are Neutral leech. This means that you can download them without having any impact on your ratio.
A public upload page is also now available for unregistered artists to easily upload torrents to the site.
For those who are curious, semi-private torrents have the private flag set with PEX and DHT disabled.