Photographers jockey for position as they wait for police to transport Justin Bieber in Miami Beach, Fla. (AP Photo/Wilfredo Lee)

Within minutes of the news of Justin Bieber’s arrest, Twitter lit up with hashtags on his plight: #prayforjustinbieber trended nationally, while “Miami Beach” and “DUI” lingered among the top-used words on Twitter until almost noon.

Part of this conversation is fueled by newsy, run-of-the-mill interest in Bieber as fallen celebrity: He is, after all, among the world’s most-recognized entertainers, and his latest disgrace constitutes international news. But it also springs from that weird, misunderstood group of tweens known as Beliebers. As of today’s count, there were more than 48 million people following Bieber on Twitter. (Granted, not all of them may be fully indoctrinated Beliebers.) That does mean, for the record, that Justin Bieber has more Twitter followers than his home country has people.

The fact that Beliebers are young (16.7 is the median age of a Bieber Twitter-follower, according to analytics tool Demographics Pro) and female (almost 80 percent) makes them easy to dismiss. It also doesn’t help that they tend toward hysteria. Make that actual, medical hysteria — some psychologists have characterized “Bieber fever” as something akin to a disorder.

But discounting Beliebers as a bunch of dumb kids grossly overlooks their cultural clout — particularly on days when they manage to hijack an entire Internet conversation. Teen girl-crushes are, of course, nothing new. (Rachel Monroe has written an extraordinary essay on the phenomenon, and its weirder manifestations, over at the Awl.) But teen girl-crushes, animated by the Internet, have taken on huge, transcendent new dimensions.

The predictable demographics of Beliebers: young, single and female. (Demographics Pro) The predictable demographics of Beliebers: young, single and female. (Demographics Pro)

Social media has engendered a sense of intimacy between artists and fans that prior generations of tweens could really only fantasize about. And more powerfully, Twitter and Tumblr (and whatever else “the kids” are using these days) have morphed 48 million semi-connected fans into a veritable community, with conventions and politics and a Bieber-centric belief system.

Those communities have issued death threats to dissidents, organized (largely unsuccessful) boycotts of TV and awards shows, and repeatedly pushed Biebs to the top of Billboard’s social chart. They’ve also helped sustain interest in Bieber between his albums and fomented interest in his current antics. Beliebers, despite their humble place on the low-to-high-brow spectrum, are like the grassroots agitators of the Internet. They’re the door-to-door canvassers and phone-bank callers of Bieber’s fame campaign. In other words, they matter, even if their space in the cultural fabric is easy to mock.

And for what it’s worth, Beliebers are standing by Justin. Mentions of the hashtag #belieber continued to trend positive on Thursday, according to the Twitter analytics tool Topsy. Meanwhile, sentiment for #bieber plummeted. You can win 48 million fans, apparently, but you still can’t win them all.

Sentiment analysis for tweets tagged #belieber (dark blue line) and #bieber (light blue line). (Topsy)