Today when I walked around hunting people, I noticed a hacker called Daveskee. He used speedhack and/or extended reach together with his friend HSDJustin, who I didnt capture on my video, unfortunately, to kill me. I decided to record it on video, and ran out with only a stone sword. As I thought, he came and killed me with his hax.
I know it looks like extended reach but it's just lag. When you run away from someone there's a time delay between you, the server and the other person's client. On their screen you're within hitting distance so their client sends the hit records to the server which accepts them.
The strange thing is something that wasn't on the video. He and his mate constantly hit me with their fist, and even though I had full iron armor and spammed food, they killed me. I took damage the entire time and got punched away I'm quite sure they have some kind of hax, even though lag played a part in that scenario on the video. At least keep an eye on them if you can C: