Yes. Technically, we know how to do federated systems. But we don&#x27;t know how to stop asshole amplification, where one person can ruin it for many others.  If someone can create large numbers of anonymous accounts cheaply, the service will be choked with spam.<p>Facebook&#x27;s real name policy is one way to stop that. Google&#x27;s &quot;one account for all of Google&quot; is another, because it takes effort to maintain a convincing fake account.  OpenID tied to cell phone numbers might work; the cell phone numbers don&#x27;t have to be disclosed to the sites using the ID for signon.  While you can buy multiple cell phone numbers, they&#x27;re not free.  So a solution to that problem might be possible.<p>It&#x27;s hard to monetize federated systems.  Note that YC doesn&#x27;t fund any.  A few exist; there&#x27;s Friendica and Diaspora, and, of course, the remnants of USENET.  They seem to have a few thousand users total.  It&#x27;s not a technical problem.