In early December 2012, a member by the name of GHO posted a thread on the forum claiming that one of his games was "broken" and provided a link to it, the page linked was the standard game page, but in the place of a screenshot, there was a string of data. Soon after the thread was posted, Fudgecycle replied, stating that "[the link] appears to be broken". Not long after, fudgecycle appeared in multiplayer not acting like himself, (member Chris32 provided evidence of this in an image he linked in chat showing him in multiplayer with the fake fudgecycle while in a Skype call with the real fudgecycle, unfortunately, this image cannot be linked as it revealed fudgecycle's real identity) it was determined that GHO's link was in fact not broken and instead contained a keylogger (according to sasruto, who posted as much on the thread before it was removed by a forum moderator) which he used to hack fudgecycle's account and pose as him. Fudgecycle has since been given his account back. Member Pacman94 was also hacked by the keylogger, but as yet, there is no evidence of this.
On the 7th of december 2012, members the_darkness and Pixelstar were playing multiplayer on Fort Haaky Saak by Pokemvp when a player appearing to be ChallengeYou appeared. Prior to his joining, the_darkness had mentioned he was British and subsequently was racially stereotyped by Pixelstar who then proceeded to poke fun at the British from the point of view that the Americans are superior. When ChallengeYou joined, the_darkness reported this to him but explained that he didn't think it was too much of a big deal. For the next ten minutes, ChallengeYou was silent and Pixelstar and the_darkness talked among themselves, until finally ChallengeYou said "I've been thinking about you, Pixelstar" to which Pixelstar replied "Oh no, this can't be good" after a while ChallengeYou replied "Within the next 24 hours your account will be terminated" Pixelstar proceeded to panic and ChallengeYou went silent for a while until the_darkness asked him what he had done about GHO and the hacking, to which he replied "I have made him a Moderator" not long after the_darkness and Pixelstar left to chat where they contacted Tinyb77, ilikegames44 and sasruto, saying that someone had hacked CY's account. ILG suggested that the_darkness create a new multiplayer game, in the hope that ChallengeYou would return and they'd be able to get some evidence that he'd been hacked, ILG, the_darkness and sasruto sat in the game for about ten minutes, during which sasruto left, until ChallengeYou joined, after a few attempts to talk to him, ILG and the_darkness concluded that CY had indeed been hacked (ILG was recording at the time to provide evidence) and soon after ILG confirmed it by opening another tab and looking at the multiplayer section of the homepage, where instead of ChallengeYou it showed an account created by GHO that day to appear as CY in multiplayer. Soon after, Pacman94 joined and, together with the_darkness, ILG and fudgecycle, he confronted ChallengeYou/GHO and forced him to confess to hacking. GHO claimed he had hacked CY in an attempt to "prove a point". Soon after, the_darkness created a forum post to warn people about the hacker, and since the 7th no hacking has taken place. As yet, no action has been taken against GHO in response to the hacking.
(Footnote: This is the 100th page on the ChallengeYou wikia)