What is a private tracker?
Most trackers allow connection to any user. However, there is some fear that BitTorrent is being slowed down by people who disconnect straight after they have finished downloading. In my opinion, this is unfounded. To tackle the percieved problem, some trackers require registration. The activity of users can then be tracked over a number of torrents, in order to ensure that everyone uploads as much as they should. Some users are pleased with this initiative, giving peace of mind that leeches are not taking advantage. However, larger sites such as TorrentReactor also somethimes publishes torrents which need registration. These are called spam torrents. If your download does not begin, check your warning messages to see if you have picked up a spam torrent, or if there is an error with the tracker. Can I start a torrent? Anyone can. How to do so is beyond the scope of this guide. For information on starting a torrent, begin here.
A private tracker is a tracker which requires registration at the tracker website (click on the tracker link in the red warning message on the general information page of the torrent) before you can use the torrent. This means that registering at Mininova won’t help! Such trackers usually have a high amount of seeds, because users get banned if their ratio is too low. See for more information the Wikipedia entry regarding private trackers.