In this case, a guy driving drunk with his friends, taking corners at 120 MPH and tweeting at the same time, died just after using the infamous hashtag.
Twitter user ink2flashyy tweeted "Drunk af going 120 drifting corners #F*ckIt YOLO". Moments later, the car he was riding in ran a red light, hit a car, hit a wall and rolled over. All five passengers were killed.
As this Twitter user states, you should really only use YOLO if the task at hand will most likely end in death. We aren't cats, the phrase isn't "YOLNT" for "You Only Live Nine Times". Be smart out there!
So please. I implore you. Don't drink and drive. And certainly don't sneer at the danger you're putting yourself in afterwards. YOLO implies that we should take advantage of the opportunity we've been given, that life is fleeting, impermanent. We should try out new things, but that doesn't mean we should take the risk of losing said life. That'd be like going to the world's best buffet and instead of trying every kind of food they have you scream swear words at a family and get kicked out.