I had the same thing happen to me but It wasn't really a major grief but I was pissed...Whoever it was destoyed all of my windows and took 12 stone stairs (My house is on a cliff...) and killed one of my wolfs....
Edit: Why did you post this on Ban Appeals? Lol?
The best way to make a sprite is If you have a handy picture ofthat sprite on a site or something so you don't too many spots and you get the colors right. :)
Are you stuck in one block and if you try to move you will just get teleported back to that block? If so then it might be a single player mod that is causing that. Just possibly...
It got fixed but like I was stuck in a little shelter I made of cobble stone and I dissconnected for the night, So I cambe back on the next day and I was stuck in there If I destroyed a block and tried to get out, it would teleport me back and it would put the blocks back. It was weird :S
Okay so I disconnected in a shelter i built away from my house because I had to go like right away and it was built out of cobble stone and now its either lag or someone locked it to where I can't destroy it. This is getting very annoying and i suggest getting anti-griefing plugins or newer...