For more than 15 years I spent time, almost every day, on a small forum for alumni of my undergraduate institution. There were a small number of very regular posters who would participate every day (maybe 30-50+), another group of less-often posters (maybe 100+) who might participate a time or two a week, and then a very large number of people who might pop in a couple of times a year.

There are (were) threads that had been going for years. Certain posters would, like clockwork, start a "Football season is here" thread year after year (made up example). There was a culture.

It was a really nice community, many people had met in person, most hadn't, all had some shared experiences, it was civil, and for many years the poster base was very consistent. I've known some of these guys for literally 15 years now.

About 2 years ago, a new member joined. He is civil, he's not a shitposter, nothing too objectionable on his own. What he is though, is completely fucking obsessive. He's always the first to comment on a new post. He responds to most comments as if they were addressed to him personally. He gets his own point of view--multiple times--out there in every single discussion.

Again, he's not rude, he's not a troll, and he's not insane (he does have an annoying tendency to humblebrag flex), he's just a super poster times ten...times a hundred.

And he has completely destroyed the community. One guy.

I got tired of seeing his name so much, and I found I've stopped reading the forum more than once a week or so. I haven't posted in a couple of months. A good IRL friend of mine commented the same thing to me out of the blue. The "familiar" names that have been ever present for many years are dropping off the forum one by one. I noticed today that a December Christmas thread that reactivated every December since like 2010 hasn't been posted in since last year.

As the longtime regulars are disappearing, new names are becoming regulars, and the tenor of the place is changing.

I guess I'm just amazed that one guy--literally one guy--was able to destroy a community than had been around for decades.

It's not really a case of gatekeeping--he is an alumnus of the school. It's not like the moderators have a rule: "Don't post too often." I don't know what could have stopped this guy. It's just crazy.