Nothing and that's exactly what would happen if it became popular.

You'd get @kanyewest7, @kanyewest289, @kanyewest3058, etc.

Also, the younger you are when you join the network, the fewer posts you get per year. If you join as an 18 year old, you have a little over 1 post per year remaining. If you join at 90, you have 10 posts per year, etc.

Inconvenience. With the second account one has to re-friend all the users from the first account. Also it would lead to bad social standing as by re-friending it will be obvious they are breaking the 100 posts per person per life rule. This could even lead to automatic bans by studying the connection structure.

That's what I want... this would force me to make a different account for every topic I might comment/post on, and they can have their own local networks. If it's a topic that I know a lot about (eg what I do at my day job), it would force a fresh start every few years.

This is in contrast to my twitter account, which is such a mess that I don't like posting b/c "most" people who will see it followed me for some other topic.