I think the police were acting illegally in this matter.
1. I don't even think it was legal for the police to demand ID from this kid. They can legally ask for ID but that in no way obligates him to show ID. To the best of my knowledge, California has no 'Stop and Identify' laws.
2. Is it even legal for them to do ID checks sweeps like this? They allow them to check everyone's IDs at certain locations but those are more the exception than the rule. On what basis did they have for engaging in such a sweep?
3. Did they even have the legal authority to order this kid to leave? I don't think they had the authority to even ask for the kids ID, let alone kick him out for not showing it to them.
4. Failure to obey a police order isn't necessarily illegal anyways. Police are limited in what they can legally do. They are police, there for our protection. They are not our overseers or drill instructors. You are under absolutely NO legal obligation to assist in police efforts to arrest you. If they tell you to stand, you don't have to do anything. Your not allowed to resist but resistence and noncompliance are two entirely different things.
You are terribly misinformed on this story.
The student was asked by the College Security Officer for ID as part of their established library rules for late night users. He refused to show ID and then to leave as requested. The CSO then went and got the University police who also asked for ID, were refused and then the punk went limp in classic passive resistance mode when the officers tried to escort him out per University rules and their legal authority to eject trespassers (refusing to leave made it trespass).
In this instance the cops where not abusing their authority but enforcing University rules and the law.