It’s understood now that, beside what we call the “real world,” we inhabit a variety of virtual worlds. Take Twitter. Or the Twitterverse. Twittersphere. You may think it’s a stretch to call this a “world,” but in many ways it has become a toy universe, populated by millions, most of whom resemble humans and may even, in their day jobs, be humans. But increasing numbers of Twitterers don’t even pretend to be human. Or worse, do pretend, when they are actually bots.