How do you handle this?

[CardSharpCook]

As for string-betting - if you're not in the hand, it isn't your place to say anything. If another player says something, please, back them up if you also saw the string bet. If you are in the hand, it is perfectly alright to selectively choose which times to call them on the rule. The dealer should be the one catching them, but they usually don't say anything. If the string bet is going to be to your benefit, it is ok to let it go. If it isn't, "That's a string bet." Tell the dealer, not the player. The dealer saw it too, but he hates being a nit so will only do something if you say something, but if you say something, he will spring into action. Address the dealer, not the player.

[pfapfap]

[ QUOTE ]
The dealer saw it too, but he hates being a nit so will only do something if you say something,

[/ QUOTE ]

Just to clarify, in some rooms the dealer is specifically instructed NOT to say anything until a player calls it out.