What these kids are doing is foolish (and it is blasphemy) but it is not the unpardonable sin.
Mention of the unpardonable sin occurs in all the synoptic gospels. Let us, as the blasphemy challenge site does, look at the account in the gospel of Mark. However, let's look at the passage in context:
22And the scribes who came down from Jerusalem were saying, "He is possessed by Beelzebul," and "by the prince of demons he casts out the demons." 23And he called them to him and said to them in parables, "How can Satan cast out Satan? 24If a kingdom is divided against itself, that kingdom cannot stand. 25And if a house is divided against itself, that house will not be able to stand. 26And if Satan has risen up against himself and is divided, he cannot stand, but is coming to an end. 27But no one can enter a strong man's house and plunder his goods, unless he first binds the strong man. Then indeed he may plunder his house.
28"Truly, I say to you, all sins will be forgiven the children of man, and whatever blasphemies they utter, 29but whoever blasphemes against the Holy Spirit never has forgiveness, but is guilty of an eternal sin" -- 30for they had said, "He has an unclean spirit."
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.
In response, Jesus emphasizes the magnitude of their sin. They saw with their own eyes. They knew better. And yet they called good, evil.
The kids making blasphemy videos are missing not one but two of the ingredients needed to commit the unpardonable sin: 1) a direct revelation from God and 2) the knowledge from which they could willfully commit the blasphemy. Instead what they are doing is just garden-variety blasphemy—presumably they have been denying God for years. Putting it on a video doesn't elevate to the level of unpardonable. What they are doing is what Paul describes, speaking of himself to Timothy:
though formerly I was a blasphemer, persecutor, and insolent opponent. But I received mercy because I had acted ignorantly in unbelief, (1 Tim 1:13)While I doubt anyone alive today even has the opportunity to commit the unpardonable sin, Paul certainly did. Had he attributed his Damascus road experience to Satan, that would, I believe, have been an example.
The premise of the blasphemy challenge is that, contrary to all of scripture, there is a magic sentence or errant thought that can render one unredeemable. There is no such thing. In Matthew's account, for example, before Jesus gives the warning of the unpardonable sin, we read this prelude: Knowing their thoughts, he said to them...(Matt. 12:25a) It was their thoughts, their hearts that condemned them, not a magic sentence.
This should be obvious. When someone comes to Christ they usually say words to the effect. But the words aren't magic. The words don't bring salvation. They simply reflect the heart. Here we have the same concept.
It is no surprise that, on other sites, I have atheists arguing with me—claiming that the blasphemy challenge is legitimate. They charge that these kids are in fact committing the unpardonable sin as defined by scripture. The explanation for their insistence is quite simple. It ruins all the fun if, in fact, Christians understand that what these kids are doing is not the unpardonable sin. Those enjoying the blasphemy challenge are getting their pleasure from the overreaction of Christians. If we give the serious but measured response it deserves—well that's rather boring, isn't it?
UPDATE: Paul (probably - maybe Liz) has a post on the same topic. With the same title!