I've not been keeping up on the "blasphemy challenge" and I don't frequent the blogs David talks about, but his discussion of blasphemy of the Holy Spirit is worth mentioning.
I used to believe that blasphemy against the Holy Spirit was simply the sin of unbelief. That fit in a nice box—those who don't believe are lost, those who do are not, ergo…
I don't think that anymore. Go to all three accounts (Mark 3, Luke 12, Matthew 12) of Jesus' warning of the unpardonable sin and substitute "don't believe" for "blaspheme the Holy Spirit" and you'll see what I mean—you get a bizarre, out of context injection of the obvious.
I believe there is a sin of blaspheming the Holy Spirit that is distinct from the sin of unbelief—it is a denial so heinous that scripture uses hyperbole and a suggestion of even greater punishment in eternity.
In the actual accounts, we see that Jesus is responding to a specific incident. Something the teachers of the law did--not just their unbelief (they may actually have believed, in a certain sense) but a real, concrete act that they committed.
The sin, at least as committed by the Pharisees, is not "just" to deny a direct revelation of God's power but to attribute it to the devil. And not out of ignorance, but willfully. The teachers knew (and Jesus reminded them of the logic) that Satan does not cast out demons. They witnessed Jesus casting out demons. They did not deny that Jesus performed a supernatural act, they acknowledged it. Yet, in spite of their training, they attributed this supernatural act of righteousness to Satan.
I'm not sure I know why David talks about the need for a direct revelation of God's power and he doesn't elaborate. That's not a part of this formulation that I've seen before and I'm not sure I agree. David doesn't fully elaborate, but he seems to be saying that you can't commit this sin without directly witnessing a miraculous act.
While I'm not at all sure that I agree that a direct observation of a miraculous act is necessary, I think David's correct that it seems pretty clear from context that the sin Jesus was referring to was the willful attribution of God's power to Satan.
Having not seen any of the videos, I can't comment on what the kids involved were actually doing, I don't believe I've ever witnessed anyone do anything that would rise to the level of what the Pharisees did when Jesus accused them of blasphemy against the Holy Spirit.