I help moderate a Usenet newsgroup. Usenet was one of the first, and is still the largest unified electronic conference medium in history. Fifty thousand groups, many gigabytes per day of traffic. Most anyone who talks about it will say "you should have seen it before [something]." The something varies. Like most open secrets, it can be ruined by exploitation. Usenet's been exploited. A lot. What was once a clever chain of heterogenous distribution schemes for news -- by which I mostly mean "news," not "stuff" -- is now sort of like swimming in Lake Erie. Doable, but you get covered in murky slime a lot and it catches fire often.
I started with Usenet in 1992 -- by that time the downward decline in the overall quality of the Internet at large, including Usenet, was getting underway. A vast influx of users ill-equipped to appreciate the majesty of the system they were using never learned to respect it, but did learn to like using it. Or abusing it, more often. And to me, in 1992, it seemed like that; a vast, sprawling pile of people talking to one another and enjoying one another's company. By then those who had come before me were already saying that Usenet was being killed by the influx. Before long I would be saying it about those who came after me. There's an obvious general rule to be extrapolated here, but I'm not going to bother.
I was part of the wave of college students to ruin it for the University students, who had ruined it for the expensive technical students. They'd probably ruined it for the DARPA researchers. In 1992, at least in the groups that I frequented, alt.* was still usable and the most common TLD you saw around was still .edu. alt.geek got maybe twenty articles a day; legitimate technical discussions went on in comp.*. alt.sex.* -- even alt.sex, probably the first large-scale open electronic sexuality forum in history -- were starting to head downhill under the crush of the untrained unwashed, but the old guard (most of those who were the elders when I got there get labelled that; hopefully they label someone before them, etc) were still posting, and with a killfile (newsreaders still had killfiles, then) you could have a pretty good time. You posted with your real email address -- spammers hadn't yet started sucking addresses out of Usenet to abuse mail with. Usenet spam was getting started, but a few killfile rules helped a lot.
And then, in September 1993, came AOL.
Now, AOL, and its kind, had existed way before this. They got started about the time I first heard a 2400bps carrier tone (other, older-guard people were there first; I respect them, but this is where I come into the story, not in 55-baud acoustics, or dumb-serial military networks. Sorry I can't be older than I am.) AOL sold for money what most of us were getting for free -- and being given by way of being students. Despite the money we laid out in tuition, most of us didn't think that paying (indirectly) for something gave us the perogative to use it without thinking. AOL, and those companies like it, sold net access, directly, for money. Perhaps most of the people who bought it were of the same mind as we -- but there came those would would abuse and exploit. And things went downhill.
The sorrowful term for this part of the story (and all time since then) is the "September that never ended," or "Endless September," or similar. Helpfully for the historians, it did actually occur in September. If a wave of college students with newfound internet access, no BBS background, and an insufficient level of etiquette was bad on its own, it was imperceptible next to the influx of the world's largest and worst ISP userbase.
"Downhill" is a long way. Eight years later, Usenet is still sliding, but hasn't hit bottom -- it somehow retained some value -- signal-to-noise is apalling, and there are large swaths of the network that are pretty much unusable. Somehow, it's hung on, despite what's continually being done to it. It's a magnificent piece of technical engineering -- no "Active Dynamic Web-Enabled Super-Duper e-i-Conferencing System" sold for tons of money since can handle the kind of load that Usenet does, get the messages there as fast, or work as flexibly. And it's been a good social experiment -- somehow, it heals itself when abused -- communities scattered by abuse form into new ones in different niches.
Using Usenet is like living in a polluted, steaming metropolis built on the ruins of a beautiful and ancient city. That city was built atop an even more beautiful pioneer town, and that atop a village more beautiful yet. There's a lot of guilt involved. Out in real life there tend to be pitched battles waged between those protecting environment and those seeking to exploit it, or those who pollute it (often because they don't realize, or they don't care enough). Same sort of story.