One possible issue with expecting players to police themselves is whether the act of policing is rewarding. Either it has to be fun, or it has to provide some other reward that they can use to find fun in the game in some other way. Like, getting in-game credit to buy things to allow them to split their time between policing and adventuring. On the other hand, if volunteering to police destructive players has no rewards, there is no incentive.
It is in the interests of the developers to find any and all ways possible to assist members of the player community who volunteer their time in this way. In the real world, police get paid and get respect, and are part of a kind of fraternity. They also (hopefully) get a personal sense of righteousness from their belief that they are doing the right thing, and a sense of accomplishment from doing a good job and keeping people safe. In real life, protection of life and property is very important. In a game, this is less true, since it's all imaginary.
Another approach is to reduce the cost of doing damage. For example, if players build something and it takes a long time, they will be unhappy if it can easily be destroyed. Unless it's easy to re-build it. Perhaps by saving the blueprint of their creation, and letting them assign virtual workers to re-build it.
All-in-all, emergence is a really exciting idea, but it's also highly risky. It comes down to providing a toolbox and/or sandbox and hoping that sufficiently creative players find it and help make it an interesting and lively environment.
BoredAstronautMember Since 18 Dec 2012
Offline Last Active Dec 22 2012 02:14 AM