For a second consecutive day at the Rio Olympics an athlete has called out a competitor for ‘drug cheating.’

American swimmer Lilly King was shown wagging her finger at a TV screen as she watched Russian Yulia Efimova celebrate her 100m breaststroke semi-final win with a “number one” gesture. Efimova served a 16-month doping suspension from late 2013 to February 2015.

King went on to win her semi-final setting up a compelling Monday night final between the rivals. NBC asked about the finger-wag following the race.

“You wave your finger number one and you’ve been caught drug cheating. I’m not a fan,” said King.

Roughly 24 hours prior Australian swimmer Mack Horton called Sun Yang a ‘drug cheat’ in a post-race press conference. The Chinese swimmer served a three-month ban in 2014 after testing positive for trimetazidine. Horton had narrowly edged out the Chinese swimmer for gold in the 400m freestyle.

“I used the word ‘drug cheat’ because he tested positive,” Horton said with Sun sitting beside him. “I just have a problem with him testing positive and still competing.”

This sort of naming and shaming of competitors is relatively rare, especially during the Olympics where athletes seek to avoid any distractions. However, athletes calling out cheaters in their sport may become a powerful weapon for combatting doping and the ones brave enough to do it should be applauded.

While the McLaren report into Russia’s state-sponsored doping regime is certainly damning, it fails to show the human impacts of systemic cheating and doesn’t provoke any kind of emotional response.

Condemnation by fellow Olympians forced to compete with questionably clean, former cheaters is far more powerful. Imagine going through the training and sacrifice it takes to become an Olympic athlete only to see a doping-linked swimmer pull past you one lane over and claim the top step of the podium. No wonder some athletes are starting to speak out more forcefully.

Comments like those made by King and Horton also places the issue squarely in the spotlight while the world is watching. Too often doping is discussed in the lead up to the games before the world is watching and then again in the weeks following when most people have tuned out.

Bringing more attention to the issue may eventually force the International Olympic Committee to come down harder on athletes caught cheating. Doping controversies cast dark shadows over what is supposed to be a celebration of sport, but if calling out ‘drug cheats’ results in cleaner competitions, it’s worth swimming in the shade.