IMO this isn't just a Twitter thing. When I ran a company, we had a public forum that, in the beginning, was civilized. As we approached about 2000 people, th

IMO this isn't just a Twitter thing. When I ran a company, we had a public forum that, in the beginning, was civilized. As we approached about 2000 people, that 5% you're talking about became so much of a problem that we had to shut them down. And in fact, it wasn't even 5% (100) people causing most of the problem: it was more like 10.