Federer already had been approached by autograph-seekers on the actual court following his afternoon practice session Saturday.
It happened for the second day in a row Sunday when a young fan sprinted unimpeded onto Court Philippe Chatrier for a selfie after Federer defeated Alejandro Falla. The 17-time Grand Slam singles champion casually walked off the court, making no effort to separate himself, but afterward he was something approaching livid.
"I'm not happy about it, obviously not one second I'm happy about it," Federer said. "It happened [Saturday] in the practice, too. And today on center court, where you would think this is a place where nobody can come on, just wanders on and nothing happens.
"So I definitely think this is [a change] that something needs to happen quickly. But obviously [I] want this to happen immediately. Normally I only speak on behalf of myself, but in this situation I think I can speak on behalf of all the players, that that's where you do your job, that's where you want to feel safe. But nothing happened, so I'm relieved. But clearly it wasn't a nice situation to be in."
The fan, who was sitting in box seats near the court, was later detained in the company of his father, according to the French Tennis Federation (FTF), and told he could not attend the tournament for the rest of the fortnight.
Federer said he was also visited by a fan during the 2009 French Open final, so Sunday's episode was his third at Roland Garros.
The situation recalled a grisly incident in 1993, when Monica Seles was stabbed in the back by a crazed Steffi Graf fan during a Hamburg changeover. Since then, tennis security has been visibly beefed up. Burly men in black, two of them on the big courts, protect the players as they sit with their backs to the crowd on changeover chairs.
But on Saturday and Sunday, no one stopped those fans from rushing the court. Federer said he had spoken to FTF director Gilbert Ysern after Saturday's incident and again moments after his first-round match.
Several hours after the match, Ysern answered difficult questions about the incident.
"Of course [Federer's] comments made sense," Ysern said. "He was pissed off with what happened in court. He has good grounds for being unhappy. I think, well, some extent it's not the end of the world. But it's embarrassing, of course, for Roland Garros when something like that happens. It simply shows that we collectively as an organization made a mistake and we will have to correct that, of course, and make sure it doesn't happen again."
The incident occurred despite what Ysern described as heightened security surrounding the tournament in the wake of recent incidents in Paris. Ysern, however, insisted there were no plans to change security procedures, and that the breech occurred due to a "lack of judgment" and later in French an "error of judgment."
"The instinct and direction of security people must have been that it was something that was acceptable," Ysern said, "which is clearly not."
Federer said earlier that Ysern had apologized to him.
"We had a quick conversation," Federer said. "I just told him what I think needs to happen. I told him about [Saturday] as well, which he didn't know about. Yeah, I'm sure they will take the necessary steps now, but this doesn't only mean for this tournament for this year; it means for all the tournaments we play all the years coming up.
"We need to make sure that it's safe out there and people don't just wander on the court like a free pass, you know. That's how it's supposed to be."
Federer said he knew Seles very well.
"I know that on these courts, people are really close to the courts," he said. "It's easy to jump above and be on the courts. If people can get close to us, to me, you know, it shouldn't happen. And then how they are going to change this? I don't know. They will tell us. Of course, I couldn't react, the kid was coming from behind me."
Later, speaking in French, Federer elaborated: "So the situation is that this should never happen on the Philippe Chatrier court in Roland Garros and it even happened [Saturday] to me. Nobody reacted in terms of safety, you know, security. I think it's true for all players that you have to feel safe when we play, feel safe on the courts. I think people should react more quickly.
"It's not just being there, standing there on the courts wearing a nice tie and suit. It's not that funny, you know. And I hope that there is going to be a reaction from the tournament. They apologized, and I must say that I appreciated this, but I'd like to see what's going to happen next."
What will happen next, Ysern said, is that security workers will be told repeatedly that spectators cannot have access to the courts.
"Tonight for sure we will reinforce the message again that clearly nobody is allowed to get on court in any case at any time for any reason," Ysern said. "It has to be very clear. Contrary to what happened this afternoon, we will enforce that rule more severely from today on and make sure it doesn't happen again."