often recordings are made of people without there consent or knowledge.
a couple of instances that come to mind are when tapes from the back of patrol cars or jail visiting rooms are used as evidence. the reason given is usually that the people didn't or shouldn't have had "a reasonable expectation of privacy", therefore since they had no reasonable expectation that these conversations would be private, the police have no need for a warrant, permission, or even notification that the recording is being made.
this would seem a similar situation, since a person giving a public speech shouldn't reasonably expect his words to be private. in fact since this recording is being made for general use and not as evidence in court, the right to record it should be even more lenient.
this has nothing in common with recording concerts or sporting events, since it's a private event, when buy a ticket and there is a contract that goes with it, most state that recordings or sometimes even still photos are not allowed.
IMO, they overstepped their authority, and destroyed private property. you'd think a supreme court justice would know better.
of course he probably also knows there could never be a ruling on it, since all they would have to do is appeal until it hit the supreme court, at which time all of the justices would have to excuse themselves since they would all have an interest in the case since it deals with their behavior on restricting recordings.