Like thousands of Colorado voters do in election season, Madeleine Scott received a postcard in the mail reminding her to vote by Election Day.

The Westminster resident had already voted, so she was ready to disregard the notice. But then something on the postcard caught her full attention: a replica of her signature appeared on the card, along with her name and address.

She said seeing these three pieces of personal identifying information all in one place set off alarm bells. Scott couldn’t quite articulate her worries, but she said something felt wrong.

RELATED | Voter Guide 2018: Everything you need to know about the upcoming Colorado election

“When I see my actual signature on something, I’m like, 'That’s not right,'" Scott said. "That shouldn’t be out there.”

The reminder postcard came from interest group Colorado Fair Share Action. CFSA went door-to-door, canvassing voters across Colorado, encouraging them to support Democratic gubernatorial candidate Jared Polis and other progressives in races across Colorado. In the process, CFSA asked voters to sign a pledge that they would vote in the general election.

“It is one of the reasons why it is such an effective tool, because people are seeing their own signatures and being reminded that they made this commitment to vote on Election Day,” CFSA’s treasurer Wendy Wendlandt said. “Studies show that actually we get more people turned out if the signature is actually affixed to the pledge itself.”

In all, CFSA sent reminder cards to about 8,000 Colorado registered voters. Each of those cards contain the voter’s name, address and digital signature replica.

The Colorado Secretary of State’s office is the agency that coordinates state and local elections across Colorado. Ben Schler, the legal and policy manager at the Secretary of State, expressed surprise that voters’ signatures were being sent on postcards.

“A voter’s signature is a very important piece of personally identifiable information,” Schler said.

When a ballot is cast, a voter must sign an affidavit that affirms their ballot is indeed theirs. Most Colorado voters submit their ballot by mail. They sign the affidavit on the ballot’s return envelope.

Voter fraud is very rare in Colorado, but the Secretary of State’s office expressed worry that personal identifying information, known as PII, printed on CFSA’s reminder cards could be used to commit identity theft, or maybe voter fraud.

“When you return that ballot, you sign the back of the envelope, and we compare that signature that you signed with the signature that is in your registration database,” Shler said. “So making sure that folks are properly using these important pieces of personal identifying information is something that is important to us.”

Wendlandt said the worries are unfounded.

“It is extremely difficult to imagine identity theft occurring through the signature in the mail,” she said. “In the case of voter fraud, somebody would have to violate a lot of laws, so they would have to be quite an unscrupulous person.”

Wendlandt said the complaint is the first in the dozen years that CFSA has done drives to get out the vote. She said her organization follows industry best practices to maintain the security of the data it gathers from voters.

“There is a lot of hype about [voter fraud] being a problem in our election system, but it turns out that there are very few instances,” she said. “The bigger concern that we have is that people don’t actually vote in a midterm election. So anything that we can do to increase that is really what we are more concerned about.”

It may be impossible to determine how many groups are collecting voters’ signatures and mailing them back in reminder to vote postcards. Canvassing groups are not required to register with the Secretary of State. They are often organized by political parties and outside groups, making them difficult to track.

The Secretary of State’s office questioned whether putting a voter’s signature on a reminder postcard was the right thing to do. Wendlandt said that CFSA is willing to discuss the issue with the office, if necessary.