Had a guy try this on a teammate last year during a match at school.
My match was over, so I was watching. My friend asked me to go get our coach.
The kid was tossing the ball as soon as he got it out of his pocket, not even bouncing it. Not a crime, but the next serve was coming no more than seven or eight seconds after the previous point was over. Quite unnerving, and it was affecting my teammate's game.
I got our coach, who got the other team's coach, both of whom told the other kid that our player had to be ready before the serve came.
That's all I've ever seen live concerning this situation, but both coaches told the guy to stop.