Micro I agree let them know by yelling. But as for casting at them, I disagree. Those who know me will recall that I spent the weekend in jail over such an incident ten years ago. Just imagine a raging king bite going on and some doughballs from out of town, for whatever reason, in front of the pier. I didn't think I'd hookup with someone's arm when I casted my Buzz Bomb. Ultimately, I got charged with assault using a deadly weapon. Long story short; I learned my lesson and try to discourage others from casting at boaters, divers, kayakers, etc. whenever they get too close to the piers. If 4-oz of lead hit someone in the head it would kill him/her.