John Oliver is a TV show host who currently hosts a show called "Last Week Tonight with John Oliver", a show where he talks about topics he feels is relevant to the current public, or should be brought to their attention. That show is currently in hiatus due to the writers strike. Before that show he worked on a "comedy news" show on Comedy Central called the "Daily Show", which was one of the most watched programs on Comedy Central. He was a correspondent there for most of his tenure, though, if I remember correctly, he briefly served as host once the original host, John Stewart, stepped down.
To why he might be relevant right now to people aware of the Reddit protests, he has stated he supports the Redditors protest even going so far as to share photos they could use of him to use in one of the forms of protest that has been going around on Reddit, which is spamming photos of John Oliver's face.
Thank you for posting this! A good friend of mine use to be pretty open minded, but he is constantly exposed to racist, sexist, abliest, and transphobic people in his family and his work. His bigotry just started out as making a "casual" joke that he "meant no offense by", but now he says the most hateful things about all sorts of people. I had tried and tried again to call him out on it, but i realized he just makes those kind of jokes around people he knows will not get offended (so he has mostly stopped with me, but some times he can't seem to help himself, which pisses me off). My SO and I are both part of the queer community and it has broken my heart to see my good friend slip into this kind of language and hate. He use to be such a safe person for me to rely on, but now is just a hateful asshole. I just recently had to cut him off because I was not getting though to him and it has been severely affecting my mental health continuing to be his friend. I really needed to read this.