So despite the hamfisted way Google has been handling the issue of real names on Google+, you have to at least give them props for realizing that securing members' identities is key to keeping its network free from scammers. That's something eBay, Craigslist, and MySpace (among others) realized too late.
The recent AirBnB nightmare is a classic example of how trusting a stranger using a false identity can have horrific consequences. A woman known only as E. J. allowed someone using a fake name and presumably a stolen credit card number to rent her San Francisco apartment for one week via AirBnB. Her place got thoroughly and viciously trashed, valuables and key personal documents were taken, her identity was stolen, and her life was turned upside down by the experience.
In this case, E. J. had placed her trust in AirBnB, which is designed to use the concepts of social networking and reputation to ensure that everyone who uses it is on the up and up. But AirBnB doesn't require its users to provide any kind of documentation proving they are who they claim to be. Now the service is facing a PR nightmare from which it is desperately trying to recover (though I still think E. J. is suffering more).
Services like Tru.ly and Trufina have attempted to blend the concepts of identity and anonymity by becoming trusted third parties in transactions between strangers; essentially verifying that you are who you say you are, and Joe or Jane Unknown are who they say they are. Yet none of these services have yet to catch on in any meaningful way.
Many people hate the idea of giving up anonymity. They like the freedom. They like having multiple identities and not having the things they say online come back to haunt them in another context. But we are rapidly entering an era where broad anonymity is something we can no longer afford.
I think over the next five years we're going to see a lot of services relying on government issued IDs, cell phone numbers, and other verifiable third-party sources before any transactions are conducted. Anonymity will become the exception (see political dissidents, above) and not the rule.
Even if you don't like it.