Lately, a player of mine caused a minor kerfuffle by his habit of touching a piece to counter blitz even when the opponent had not finished the move.
Interestingly, I found nothing in the rules (admittedly by a quick browse) prohibiting grappling ones own pieces while not having the move, even §4.3 "touch-move" applies only to the player having the move!
To unruffle his rather annoyed opponent (incidentally also the tournament director), after clocks were halted, I politely explained to him that even the allowed counter blitz (not waiting for the opponent pressing the clock) is, even though allowed, at least bad style in my opinion and asking for havoc under Fischer mode (for the record, it was normal 15' quick) - and what he does is asking for a likewise sportsmanship opponent to change his mind where to put the piece and claiming touch-move. I promised him to ask a rule forum what exactly is allowed and what not.
It was always my opinion that a player not having the move should not touch anything, neither for j'adoube nor premove, lest him getting the book thrown at. What should the arbiter do when a player not having the move touches a piece with the intention of counter blitzing?