American swimmer Michael Phelps - who turns 31 today - became an Olympic legend in 2012 when he became the most decorated Olympian in the history of the games. But a few years earlier, Phelps endured one of the greatest lows in his career when he became arguably the most memed Olympian, due to the media circulating a picture of him smoking a bong.

Shortly after, Phelps admitted that the picture published in 2009 was authentic, apologized to his fans and accepted the repercussions, which included a three-month suspension from USA Swimming and the discontinuation of his Kellogg's sponsorship. (Which probably has enough trouble dealing with Toucan Sam's dependence on Froot Loops.)

Phelps also refused to take any outs when it came to mitigating his responsibility. During an interview before the 2012 Olympic Games in London, journalist Piers Morgan suggested that the scandal was overblown because of who Phelps is, rather than the severity of what he did.

"To me, the mistakes you've made are not massive mistakes. They were made to be apparent massive mistakes simply because of who you were. I remember the bong picture coming up. And I remember laughing at people and saying, 'Really? This is a scandal of epic proportions?'"

But the swimmer refused to pass the blame off on the media. "With every mistake you make, you obviously have to pay for the consequences that come your way," Phelps said.

Will legalization make cannabis okay for Olympians?

But times have changed since the Phelps scandal. In 2009, recreational marijuana use was illegal in all 50 states. But right now, Phelps' actions - from a legal standpoint - would be no different in certain states than if he were pictured popping champagne corks like professional baseball players do after winning the World Series.

However, the acceptability of marijuana use among Olympians isn't likely to change anytime soon. In 2012, ESPN's Devon O'Neil wrote a feature story about Olympians and alcohol sponsorships, which athletes tend to shun because of the impact those deals could have on their public image. After noting that some surfing and cycling athletes have dabbled in pitching alcohol, O'Neil writes,

"Still, the surprising figure is not how many athletes have alcohol sponsorships but how many don't - a reflection of the danger involved for both sides, despite rich potential. Consider the case of [American] snowboarder Scotty Lago. The 2010 Olympic bronze medalist in halfpipe...is also one of the sport's most popular film stars and most marketable athletes. Yet when Jose Cuervo representatives expressed interest in sponsoring him, his agent, Circe Wallace, said they declined because the potential risk exceeded the reward."

That risk involves potential damage to an athlete's reputation, given that much of an Olympian's fanbase is comprised of minors.

"Ultimately, when you're gearing toward a young demographic and as an ambassador for your sport, to encourage drinking is a questionable move," Lago's agent told ESPN. "It's probably better for your long-term earning to remain somewhat neutral. I would only recommend it during an athlete's twilight years, or if they're involved with something gnarly like big-wave surfing that appeals to a more mature audience."

So recreational marijuana use will likely remain taboo in Olympic sport for some time.

But the IOC's attitude toward cannabis is changing

The Olympic flame in Sochi: the World Anti-Doping Agency (WADA) had relaxed its policy on marijuana use in time for the 2014 Olympic Games.Ververidis Vasilis / Shutterstock.com

The stigma around Olympians using marijuana might not change anytime soon. But the treatment of athletes who have a casual puff now and then has changed dramatically. In 1998, Canadian snowboarder Ross Rebagliati was stripped of his gold medal after testing positive for cannabis use. He later regained his award through appeal, but he wouldn't have lost it in the first place had the incident occurred today.

Although cannabis still appears on the list of banned drugs issued by the World Anti-Doping Agency (WADA), which oversees drug testing in the Olympics and other sporting events, WADA has raised the threshold for a positive test considerably since the Phelps incident. .

In 2014, Paul Waldie of the Globe and Mail reported that the accepted level of tetrahydrocannabinol (THC) in an athlete's system has been raised considerably, from 15 nanograms per millilitre of urine to 150ng/ml.

"Officials say that means an athlete who smoked some weed before the Olympics, or inhaled second-hand smoke, wouldn't likely test positive in Sochi," wrote Waldie. "Someone who failed the new test would have to be 'a pretty dedicated cannabis consumer,' WADA officials have said."

Marijuana became a more socially acceptable drug

Athletes such as Ross Rebagliati and Michael Phelps no longer lose the opportunity to win medals for consuming moderate amounts of marijuana.

The rules were altered to reflect changes in the legality of marijuana. Arne Ljungqvist - a member of WADA and the International Olympic Committee - told Waldie that the threshold was raised because "[marijuana] is a socially more or less an accepted drug being used in social context."

And while it remains on WADA's blacklist, cannabis is listed among substances that are banned for moral reasons.

"WADA also uses three criteria for including drugs on its banned list; performance enhancement, danger to health and a violation of the spirit of sport," Waldie explained. "Marijuana generally falls under the last criteria, which is a nebulous concept that includes ethics, honesty and 'respect for self and other participants.'"

So athletes are asked to be good sports and put the bongs away while competing, but they won't likely lose a medal over having a joint now and then.

Click here to learn if Michael Phelps weed use would have passed the Olympic drug testing.

h/t The Globe and Mail, Sports Illustrated, ESPN.

Banner image: Michael Phelps at the 2009 Santa Clara Grand Prix (JD Lasica / Flickr.com)