I've wondered such things myself, but it sorta depends on the industry as to where the limit should or could be.

It's one thing to have multiple search or email providers, but how many companies can afford the investment for a new silicon fabrication plant? Or to construct a new airliner that meets our reliability and safety needs? Some industries seem to require immense sizes for the entities to be viable at all.

And when it comes to Facebook, I mean, we can't split this up like we did with Standard Oil. People want to be connected. Not unless we mandated some kind of social networking standard that could federate...