That's quite a different issue, is it not? The spam bots come because the social network is successful, as they will come to any other network regardless of real name policy.

What I'm saying is that anonymous accounts will prevent that success in the first place, because of the behavior of non-spam users. At least for a mass market product most regular folk would want to use, like Facebook.

The real name policy is barely enforced by FB, as long as a name is basically plausible they don’t even bother.

We don't know what the services would look like without a real name policy.