With the current setup I see two issues:
Unlimited users: They pay more, but there are plenty who abuse this. They use the machine very excessively, causing resource starvation for the other people. As far as I am aware the next "setup" will remove the Unlimited Plan. We will see. Point is, if there is no system to distribute resources fairly, they could get moved to a separate area.
Free users: Anyone can abuse this system. If we share IPs, I am sure botters/cheaters/hackers will use the service and will make companies block LS IPs everywhere.
Why pay-by-credit users are no problem: They shut down the machine once they are done to save credit, otherwise they just keep paying. It's a win-win situation.