What if the Blasphemy Challenge had not been a gimmick to raise awareness and promote debate about fundamentalism, but instead had been a covert Christian group harvesting the names and addresses of sinners? (For the record, they're legit -- I got my free DVD.)
If you haven't heard of the Blasphemy Challenge, it is a project by the Rational Response Squad to raise awareness of the ridiculousness (and danger) of fundamentalist religion. They are using an interesting bit of Christian gospel as their example:
"Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men." -- Jesus in Matthew 12:31 (KJV)
"But he that shall blaspheme against the Holy Ghost hath never forgiveness, but is in danger of eternal damnation." -- Jesus in Mark 3:29 (KJV)
"And whosoever shall speak a word against the Son of man, it shall be forgiven him: but unto him that blasphemeth against the Holy Ghost it shall not be forgiven." -- Jesus in Luke 12:10 (KJV)
In other words, you can be forgiven for raping a baby seal (of the same sex, even!) but not for doubting in the existence of an invisible ghost. Is that screwed up, or what? (Luckily, most Christians don't follow the Bible literally, even if they claim to.)
The gimmick is this: Post a video of yourself denying the existence of the Holy Spirit (apparently this counts as blasphemy) to YouTube, and you get a free DVD!
Hundreds of people have participated (including myself), and I have to wonder how many of them even questioned whether the operation was legit. The Blasphemy Challenge folks did not have to do anything other than advertising to get the meme started, and it built upon itself quite rapidly. All of these folks sent in their mailing addresses to an unknown party.
How easy would it be to conduct a scam using similar methods? A fundamentalist Christian group could have used the very same technique to collect the identities of "sinners needing to be saved" and distribute the information to local groups who could show up on people's doorsteps and try to proselytize. A phisher could run a very different campaign and gain some amount of personal information. A corporation could run a guerilla marketing campaign to identify potential consumers. How readily will people divulge private information to unknown parties in exchange for some promised good or service that has not been verified in advance?