Should Rangers fans have interfered?

ARLINGTON, Texas -- That seems like a strange question, doesn't it?

But as Kinsler's 3-0 foul pop in the ninth headed toward the first row of seats down the first base line, I wondered if the fans might try to catch the ball. But none of them really made a move at it, allowing Daric Barton to lean over and make the play.

It got me thinking about fan etiquette. What's the proper thing to do in that situation? And if the fan interferes obviously, what might the umpires do?

It's tough when you see a ball coming at you not to try to grab it. I was surprised the fans backed off. What would you have done? What should those fans have done?