As the debate over how to fix slow play rages on in golf circles and the PGA Tour’s Player Advisory Council, some of the biggest names in the sport are taking to Twitter to voice their opinion.

But as Luke Donald found out Wednesday, with Twitter comes Twitter trolls, including the one and only Phil Mickelson.

Earlier this week, Mickelson strongly defended the use of green reading books in relation to slow play, saying, "For anyone to say they slow up play is flat out idiotic."

Donald commented on Twitter, making the case that banning the books would speed up play. Unfortunately, he led off with, "Guess I'm an idiot then."

He should have known better. Sometimes Phil just can't help himself.

"We agree on one thing at least," he shot back.

There's valid arguments on both sides of this debate, however, there seems to be a clear winner in this round.

And in case you were wondering, Mickelson enjoyed his comment just about as much as all of his followers.