Shot again
This sign was made famous from the ‘GTA’ or ‘Grand Theft Auto’ video game series. On one of the loading screens, you see this sign and the dark sense of humor it has. It is trying to tell anyone who would even think of trespassing to think again because you will be shot multiple times.
Even if you were shot and survived, you would now face being shot again and the owner would finish the job without any emotion towards you. If that was not a clear enough indication for you to stay away from their property, we do not know what is. Always be reading signs folks.