I remember a glitch that happened to me a few years ago, it happened frequently then to players. The glitch was that you would go through a portal and it would fling you across the map, where you would have to go back to the portal and go through it again for it to work. Another glitch I encountered was the time that I went through a map and appeared controlling someone else's character. Apparently I looked like myself on everyone else's screen, but I wasn't controlling my character and when I would move, the character would be a bit jerky and hard to control. I don't know if these issues still happen now, but they were interesting and funny to say the least.
