So they can only get sued if it only pisses one person off?

Nah, class actions are a different animal altogether.
http://en.wikipedia.org/wiki/Class_action
In theory it's used as a deterrent to organizations screwing large groups of people over wholesale. In practice it usually involves a group of trolling attorneys seeing an opportunity for a class action, passing around a form promising qualifying wronged persons some kind of token award (free hat!), and then said attorneys making a ton of money if they actually win a settlement.