Here's Fox News host Neil Cavuto talking with a producer at 12:10PM, recorded on a live mic (update: Cavuto was in Sacramento):

CAVUTO: Any estimates on how many people are here?

PRODUCER: No, we're trying to get...

CAVUTO: There's gotta' be 5,000.

PRODUCER: Oh, at least. You know, I mean the cops aren't going to tell us, and we've been trying to get ahold of the PR person to give us their number, but I think 5,000. You can say it's starting at 5,000 [unintelligble, but sounds like "and maybe it's more."].