I have also been battling this blasphemy challenge. I wrote emails to youtube asking them to pull down these video postings. I have contacted AFA and several other Christian organizations to rally support against this. I also sent emails to all of their advertisers to make them aware of what is being allowed to be performed through youtube, Here is an example of a letter that I sent to the advertisers:

To advertising partner of YouTube:

I have noticed that you are advertising on YouTube. Did you know that YouTube is allowing the blasphemy challenge to be a part of their website. http://www.blasphemychallenge.com/

As an advertiser on YouTube, I wanted to make you aware of this activity and to warn you of any adverse responses to your advertising with them.