Trip to SCOTUS, Camreta v. Greene (09-1454) or: "Justices just want tohave fun"

I usually write about technical topics in this space, so pardon my digression. </metablogging>

Today my AP Gov't class took a trip to the Supreme Court of the United States (SCOTUS). We were fortunate to get reserved seating thanks to one of my classmates, so we skipped the line and were able to sit for an entire argument. We didn't get to choose which of the two arguments we saw, since half our group was randomly sent to each. I didn't get the one I had hoped for. Camreta v. Greene (the one I attended), however, proved to be much more entertaining than Schindler Elevator v. US ex rel. Kirk, at least based on the people I talked to. A quick search of the transcripts for each confirms this:

Argument
    # of instances of "(Laughter)"
Camreta
12
Schindler
0

Facts of the case

The Huffington Post has a detailed overview of the circumstances surrounding the case, which didn't gloss over any details or strike me as overly biased; they certainly did a better job than I did. The whole story is rather sad, but what came before the court was this: whether a child can be questioned by the police, Child Protective Services, or other governmental agencies without parental consent, probable cause, or "extingent circumstances". If so, on what grounds can such questioning occur?