Paris: Roger Federer admits he can see the funny side of players whipping out mobile phones on court, but warns they could also undermine the game's integrity.
Sergiy Stakhovsky of Ukraine used his phone to take a picture of a contentious line call in his French Open first round defeat to Richard Gasquet.
France's Gael Monfils, meanwhile, took his phone from his bag to film the Court Philippe Chatrier crowd peforming a 'Mexican wave' during his second round victory over Ernests Gulbis on Wednesday.
But Federer believes that mobile technology can also create problems for the sport.
"It's happened before. It's only going to happen more. Wouldn't be surprised if they change the rules because of it again," said the 17-time Grand Slam title winner.
"If you do it, fines are going to be more severe. I think it's pretty funny. The problem is that clearly there could be coaching going on and all these things through mobile devices.
"Probably be so easy to do. Go to the toilet and you hide it somewhere in the toilet. I'm just saying anything is possible.
"You have to hope that the players use it in a funny way and it's not meant to be bad or disrespectful."
Stakhovsky, the world 101, posted the picture of what he believed was a bad call in his loss to Gasquet on his Twitter feed.
"Something just itched in my butt -- it was a spontaneous thing to do," he told AFP.
"But it was wrong. The rule book says you can't do it. I had a nice chat with the umpire. It was more a joke than anything and I hope people won't judge me that badly."
Monfils said he had asked the chair umpire for permission to film the crowd who rose to salute the home player after he had taken a two sets to one lead against Gulbis.
"I ask, Can I be allowed to tape the wave? He tells me, Sure, you can. So I say, Okay, I will tape it, like quick. No worries."