Twitter is at the heart of yet another controversy, this one involving Internet viruses and spam.In the span of just a few fascinating months, Twitter has evolved from a meaningless chirp in the woods, to canary in a coal mine, to alarmist, to champion of democracy.

One member of the Obama Administration would like it to receive the ultimate in secular sanctification, while others would like to see it quarantined as a disease vector in itself.

Talk about the Perils of Pauline; if Twitter were a person, it would have signed a Hollywood deal by now, with Ashton Kucher in the lead role (or Demi Moore for that matter).

Once upon a time, Twitter was just a minor character in the moving picture that is social networking, recognized as a small part of something Barack Obama used to become President of the United States.

Just as it was losing its luster (and reportedly losing defectors faster than it was gaining converts), along came the Swine Flu to bring it back to prominence.

No sooner had everyone realized they weren't dying from the pandemic than they turned against Twitter for being the Cassandra that yelled fire in a crowded theater.

Then, of course, came the Iranian elections, and Twitter once again became an invincible hero of democracy.

Invincible, that is, until it turned out that evil marketing geniuses, spammers and cybercriminals have learned to use Twitter against the general population. Now Twitter is bad again.

But as Sarah Perez has so neatly put it, Twitter doesn't need more policing, we just need to be smarter about policing it ourselves.

Our deputy national security advisor, Mark Pfeifle, thinks Twitter founders Biz Stone, Jack Doresy and Evan Williams should get the Nobel Peace Prize for devising a tool that helped Iranians spread the word about what was really happening in their country. That's plain silly.

But the truly fascinating thing about Twitter is this star quality it has, by which it galvanizes attention; Web 2.0 finally has its avatar, the thing in which people see whatever they want to see. Twitter is important now in the same way that leading e-commerce sites were important in determining how that whole Internet thing was going to turn out. The question is, is Twitter Amazon.com or Pets.com?