Public trackers are rare these days. I would almost tell you to avoid them. My suggestion if you are trying to stay free and dont care about letters from your ISP in the mail is to wait for iptorrents to open up invites by watching the tracker list here. You can also try for the others on that list that do random open registration events. You can see the open ones by sorting by availability. Be careful if you do get into iptorrents because you have to maintain ratio. They are super ban happy there if you dont.