VidCon
VidCon is an annual convention for YouTube creators and fans to meet up. Greg has an odd history with VidCon.
2011
During the peak of the Onision channel's highest subscriber rank and after the first wave of 2011 relationship drama, Greg attended VidCon 2011, which took place in the beginning of August. He uploaded a few videos while there including vlogs and a VidCon version of the Banana Song featuring fans and other YouTubers at VidCon. ($ource) VidCon 2011 was also where the legendary Shane Dawson and Onision kiss took place. (Source)
When talking about his VidCon kiss with Greg in a 2015 video, Shane revealed Greg was wearing a bulletproof vest at VidCon 2011. (Source) The vest could be seen in clips where Greg was not wearing his banana costume. During this time, Greg would occasionally speak in videos about how he believed he could be assassinated for his strong opinions.
Greg uploaded several videos revolving around VidCon 2011.
2012 Ban
After a solid year of constant public relationship drama and negative attention for the Onision channels, parents (or what Greg suspects to be haters pretending to be parents) began contacting VidCon concerning Onision being on the VidCon 2012 Guests and Speakers list. Soon enough, Greg's name mysteriously disappeared from the list on the VidCon website. After becoming aware of this, Greg made a string of Facebook statuses about his disappointment in VidCon and blaming haters for getting him off the list. (Source) He encouraged fans to tweet VidCon to demand answers and a refund if they purchased a ticket to see him. (Soruce) In response, an employee from VidCon contacted Greg and told him he would no longer be a speaker due to the parents' requests, but he would still be allowed to attend the event. After this, Greg made a status thanking his fans for tweeting. He said even if they apologized, it wouldn't matter. He decided he will not attend VidCon ever again. (Source)
Later that day, Greg uploaded "CENSORSHIP ( @Vidcon vs @Onision )", which was later renamed "Parents vs Onision". In the video, he explained what had happened and talked about what the employee had told him. Greg concludes this is all because they do not want him to voice his opinion. He compares his comedy and 2011 event appearances to Shane Dawson's. He says Shane cursed and joked about pedophilia, but no one complained about him. He also points out that although Shane is more popular than him, others that are less popular then Greg are speaking. Greg concludes the difference between him and Shane is that Greg has opinions on vegetarianism, circumcision, and religion that parents don't want their children to hear. He complains he is being censored and there is an unfair biased against him due to his opinions. He threatens to not even attend VidCon because they were not supportive of him and removed him from their site. ($ource)
The next day, Greg received an email from YouTuber and creator of VidCon Hank Green. In the email, Hank explains he is upset at the employee that removed Onision because they did not ask for Hank's permission. He says Greg was never going to be a speaker, as he was listed under the "Guests" portion of the Guests and Speakers list. He concludes because the recent controversy, he believes it might be too unsafe for Greg to attend. The controversy he is referring to most likely is about VidCon and the recent backlash over Greg's A Horrible Rebound video. Hank also mentions he does not agree with everything Greg or others attending VidCon says and that he's grateful to live in a world where you can say what you like. This is most likely to clarify he was not removed because of his opinions. (Source) Greg reacted to the email publicly on his Facebook saying he still would have gone if people threw stuff at him, as long as he got to meet his fans, but now he officially will not be able to attend. (Soruce)
The next day, on January 25, Greg uploaded "Why I Cried". In the video, he says the previous night be became depressed and made a Facebook status saying he felt like crying. He explains this was because he won't be able to see his fans at VidCon because the haters threatened him. He says after watching a movie where a character kills himself, he cried uncontrollably, even though he was trying not to let haters make him cry. He says the haters made them cry and broke him down by taking away a happy event in his life. ($ource)
Post Ban
It is speculated Greg's ban was not permanent, only for that year, but Greg chooses not to attend.
Since the ban, Greg occasionally makes negative remarks toward VidCon and Hank Green. (Source) Especially when it gets close to VidCon every year.
2015
When VidCon 2015 began approaching, Greg, in usual fashion since his ban, began tweeting about how he would not be attending VidCon and how he wound not want to attend anyway. (Source) Unlike previous years, he eventually began making comments and social media statuses trying to convince his followers that Vidcon was not a safe place for young female fans, saying web celebrities could be sexual predators. (Source) He even went as far as to take a photo of Shane and a fan from VidCon, block out Shane's face, and caption it "Vidcon: Pedophile heaven."
During this time, Greg had been following the story about the Viner Carter Reynolds, whom allegedly sexually assaulted his girlfriend in a leaked video. (Soruce) Greg tweeted about the story several times and even tweeted at Carter, scolding him for his actions. After word began to spread that Carter attended the first day of VidCon 2015, that night Greg began tweeting Hank Green, notifying him of Carter's unwanted presence at the event. This started a twitter dialog between Greg, Hank, and Carter, which ended with Hank concluding Carter was not welcome at VidCon. (Source)
Ironically enough, after trying to convince fans VidCon was too unsafe to attend, Greg was viewed as a hero of VidCon 2015. Many internet media websites following the Carter story credited Greg with helping Hank Green get Carter banned from VidCon.