Preventing online harassment can be tricky. For many apps and services, it falls into a self-policed gray area where a user's only option is to block the offending harasser. And the fact that people rarely experience consequences for acting inappropriately online is part of why it's such a problem in the first place. However, justice is being served in at least one case: An Australian man is facing serious consequences for making sexual threats on social media in what BBC News is calling “a landmark victory for opponents of online harassment.” Here’s what happened.Zach Alchin, 25, was sent a screenshot of a Tinder profile belonging to Olivia Melville last August. Melville had lyrics to the song “Only” by Nicki Minaj and Drake on her profile, which, as fans may know, touches on some adult themes. Alchin editorialized on her choice by commenting “Stay classy, ladies,” and blasted her once-private profile to the world on Facebook.As if this blatant slut-shaming wasn’t enough, the post quickly garnered abusive comments about Melville from other Facebook users. Alchin continued to write several more extremely offensive posts after Melville’s friends tried to defend her online. BBC News reported that Alchin's more than 50 subsequent posts included "rape threats, derogatory comments about feminists, and declarations that women should 'never have been given rights.'"Eventually, one of Melville’s friends reported Alchin’s abuse. Following his arrest, he admitted posting the comment but insisted he was unaware that it was a criminal offense (oh, and that he was drunk when he did it). Alchin originally pled not guilty to the charges of sexual threats but changed his plea to guilty on the opening day of his trial, BBC News reports As a result of these events, Melville and others started an online sexual harassment advocacy group called Sexual Violence Won’t Be Silenced . Alchin, who is the first person to be tried in court for threats made over social media in Australia (and one of a very small number who've been tried or sentenced for this crime globally), will be sentenced in July and could face up to three years in jail.