Shay Carl
Shay Carl is a very well known YouTuber that has been popular for many years. Greg's first major YouTube drama took place when Greg attacked Shay Carl on Twitter in 2010.
Events
In June 2010, popular family vlogger Shay Carl announced that his newborn son was circumcised.
Greg decided to personally call out Shay Carl and attack his character by calling him names such as "child mutilator", "monster", and "horrible father" on Twitter over a period of a few days. (Source) This caused arguments on Twitter between and Onision defenders and Shay Carl defenders. YouTuber Jpmetz made a video in defense of Shay, which lead Greg to make a video response.
Shay's only response to Greg's attacks was, "@Onision Un followed me on twitter. I just feel bad that he is so angry and that I discust him so much. I have no hard feelings for him." (Source)
Eventually, Greg apologized on twitter for his tweets getting personal, but refusing to directly apologizing to Shay Carl. (Source)
Aftermath
By 2011, Greg and Shay seemed to be back on good terms again. In July 2011, Greg made a Facebook status: "Shay Carl was so nice to me today. I really appreciate his kindness. His optimism & general loving attitude is something to be sought after." (Source)
In a 2012 live chat, Greg went on to explain why he did what he did on Twitter back in 2010. He states that he is an "attention whore" because he is dramatic, but he does not attack YouTubers just to get more fame. He states the reason he said "mean things" about Shay Carl on Twitter was because he just had a heated conversation about circumcision and he "lost it" because he really hates when people circumcise there children. He goes on saying that he did apologize for personally attacking Shay Carl. He says he believes and Shay are on good terms and that he should have never said anything that destroyed his character or made him look bad. He said it did not make Shay look bad because everyone was on his side and "the only thing that got hurt in this situation was me for standing up for his kid, which really wasn't my place." He says it's not his business to get involved with other families, but he would never cut his child.