The nether portal 'bug' (if you can call it a bug) has been around for a long time now, but it has began to be very annoying. If on a server (maybe single player too), the first player to create a portal pretty much owns ALL portal exits. Sometimes portals will appear randomly in the world if the first portal is destroyed. This creates greifing, as the player to create the first portal can have everyone in his home just by players exiting the nether. Also, players will have to walk all the way back to their house because they did not exit through their own portal. I think portals should work like this: Get the cords of the portal being entered, and make a copy of the portal in the same cords of the nether. This way everyone can have their own private portals, without bumping into others.