Banned for grief?

[zELITEzRAPIIDz]

I was playing on the server like i usually do and i did nothing wrong. i disconnected to go for lunch and when i attempted to join back it said "kicked while connecting to mcz: grief" however i have not greifed at all. I do not understand why i have been banned, is it possible you could shed some light on the subject and perhaps have me unbanned?

[Zedwick]

You have been banned for killing another players' horses.

[zELITEzRAPIIDz]

Another players? i found horses in a field and killed them but i did't know they belonged to anyone