No worries! Aimee Challenor is a very minor political figure in the UK who's mostly known for the fact she hired her father to act as her election agent after he was charged with (and was later convicted of) truly horrendous crimes against a ten year old child. Later on she left politics entirely and began working for the Reddit Public Access Network, after which she was eventually hired as a site-wide administrator.
On /r/ukpolitics (a fairly large subreddit) a moderator posted an article from the Spectator that mentioned her indirectly, I believe simply naming her as a candidate at the time and not mentioning her background at all. This moderator was banned without warning from Reddit and it became known that Reddit had been systematically censoring any mention of Challenor whatsoever and worse, banning the commenter. It was claimed by Reddit this was through an automated system but it's been alleged that Challenor herself was carrying out the censorship personally*. /r/ukpolitics temporarily closed itself in protest of this behaviour as they (correctly, in my opinion) felt that it was absurd to ban legitimate discussion of a British political figure on a forum dedicated to British politics simply because they're also a Reddit administrator and at any rate they wanted to support their banned fellow moderator.
This started a chain reaction across the site in protest of Reddit's administrator team in which many subreddits with millions of subscribers set themselves to private in solidarity with /r/ukpolitics. I don't have any figures to hand but participation was very wide and I can't imagine it did that day's advertising revenue any favours at all! Eventually the administrators relented after intense criticism from almost all angles, fired Challenor and re-instated the banned /r/ukpolitics mod. The moderators of /r/ukpolitics handled the situation excellently in my opinion, their competence was in stark contrast to the incompetence of the administrators.
It's worth pointing out that it was the censorship on Reddit's part and Challenor's questionable conduct as a political figure that triggered such a strong reaction, not Challenor's political stances. From what I understand her political activism was mostly centred around environmentalism and LGBT rights, both very laudable causes in my opinion! I think the issue everyone had was that while harassment is never okay (and I don't think it's controversial that people often do suffer atrocious harassment on platforms like Reddit, especially transgender people) the reaction to it was extremely disproportionate and further complicated by the fact Challenor is a public figure - even if a very minor one. There were also apparently a lot of complaints around the issue of safeguarding minors on Reddit which followed on from their obviously inept hiring practices, although I don't know enough to comment further on that.
>More likely it will be a slow fade to unimportance, like MySpace or Facebook (the platform, not the company).
This could be a more likely outcome than what I suggested, although given how volatile politics on social media are these days I could definitely see Reddit tearing itself apart over moderation drama. Having said that this isn't always terminal, a good case study would be 4chan which has had several incidences over the years of parts of its userbase starting their own platforms with the same format.
*I'm still not sure about this, as a web developer I can't imagine Reddit with their enormous volume of traffic would seriously follow every outgoing link and scrape the page for mentions of Challenor. I think it could be done, but I don't think it could be done with good value for money! I'd appreciate someone with more experience than me weighing in on this.