A computer disk that the Minnesota Republican Party prepared to support a ban on gay marriage has another purpose: gathering data on the politics of the people who view it.

That's stirred up a technological tempest on the Internet and among Democrats who say the disk will improperly gather data from people who run it on their computers.

Privacy experts say they're concerned that the GOP won't adequately warn users that it's collecting the data, and they worry where the information will end up.

But GOP officials said the final version of the CD that's due to be mailed soon to hundreds of thousands of Minnesotans will contain a notice that the information gathered may be used by the party.

The disks contain video clips from Gov. Tim Pawlenty, Secretary of State Mary Kiffmeyer, State Auditor Pat Anderson and House Speaker Steve Sviggum. They talk about what they consider the dangers of gay marriage and why they believe a constitutional amendment is needed to ban it.

To watch each video, a person has to go to an Internet site and punch in an ID code that tells the party who is viewing it. Once the video is going, viewers are asked questions on subjects like abortion, gun control and party preference.

Party officials distributed what they called test copies of the CDs to the media on Monday. Those disks contained no disclaimers saying that data was being collected and transmitted.

Political parties used to collect voter information by canvassing citizens one by one or paying for subscriber lists. Minnesota GOP spokesman Mark Drake said the CD is just the latest way to collect information.

"It's an ageless part of American politics, and I don't think it's anything that is particularly a big deal beyond that it's high tech," he said. "It's not different than 30 years ago filling out a voter survey in your kitchen and then mailing it in."

Drake pointed to recent Internet surveys by Democrats and the teachers' union Education Minnesota as similar examples.

But some privacy advocates disagree. They said someone who fills out a survey on those sites is knowingly providing the groups with information, while it's not clear from the Republican CD that the data is being transmitted back to the GOP, or even what other data about the user is being collected.

Lillie Coney, associate director of the Electronic Privacy Information Center, said the GOP CD should clearly indicate that the packet is not only a video on gay marriage but a tool to collect voter data.

"Anytime the consumer is providing information to an entity and they're not aware of how that information is being used or what purpose the information may be put to, they're at a disadvantage," she said.

Coney also had concerns that the data could be accessed by a third party.

Christa Heibel, CEO of CH Consulting, a Minnesota company that produced the disks, said firewalls have been developed to ensure that the voter information is protected.

But she spoke after Minnesota Public Radio was able to access some of the data that was collected during testing. MPR discovered that data collected by the CDs were being sent to a computer server that was not secured, potentially making personal information in the database vulnerable to snoops.

The GOP said the server will be fully secured when the CDs are mailed. And Heibel said it should be apparent from the final packaging and other means that voters will be sharing information with the party.