Limit the amount of active users until they prove they can safely run a platform of a certain size. It's like how buildings have max occupancy levels in case of fires. If a club is super popular, they don't get to cram in as many people as they can then claim "it's really hard to safely run a club with this many people, so you can't hold us accountable" whenever people are trampled to death trying to get to the exits during an emergency.