A citizens group is challenging hundreds of vote-by-mail applications in southeastern Pennsylvania, claiming they were filed by voters who moved to a new address that disqualifies them from voting in the state.

The contestants, who apparently work as organized activists in several counties, argue that those voters are ineligible for a mail-in ballot because the address on the state’s mail-in ballot request file does not match an address connected to voter’s name from a US Postal Service database.

This method of cross-checking has been regularly criticized by election experts as insufficient to confirm that the records refer to the same person.

The appeals filed with the counties allege that the voters are no longer Pennsylvania residents and therefore are not eligible voters and cannot receive a mail-in ballot.

The challenges apparently cite data from the Postal Service’s national change-of-address database that shows a record that someone matching the voter’s name filed a change of address for mail delivery.

Pennsylvania law requires that someone be a resident of Pennsylvania to be an eligible voter, but does not require that their Pennsylvania address be where they receive mail.

A coalition of voting rights groups rejects the challenges, calling them a “malicious attempt” to disenfranchise voters.

“We are deeply concerned about the validity and intent of these challenges, the deliberate abuse of the election system, and the time and energy it will take our local election officials to address,” said Susan Gobreski, president of the League of Women Voters. from Pennsylvania. “We will defend the freedom to vote for all Pennsylvanians.”

Under Pennsylvania law, vote-by-mail applications can be challenged until 5 p.m. the Friday before the election — for a fee of $10 each — on the grounds that the applicant is not qualified to vote.

The challenges appear to be a coordinated effort. Broad and Liberty, a conservative news outlet in Philadelphia, reported Monday that it reviewed a list of 865 challenges targeting registered voters in Bucks, Chester, Montgomery and Delaware counties. Broad and Liberty did not name the group behind the effort and reported that the challenges are mainly aimed at requests from Democratic voters.

Votebeat and Spotlight PA confirmed with Bucks County that its elections office received 191 challenges from the same person on Friday. Spokesman Jim O’Malley said a board of elections hearing would need to be held to determine the validity of the appeals and that the hearing has not yet been scheduled.

Chester County spokeswoman Rebecca Brain said the county received 212 challenges, all using the same standard form, and that a board of elections hearing was scheduled for Friday to review the challenges.

Megan Alt, a spokeswoman for Montgomery County, said the county has not yet received any challenges but will address them if they come. Jim Allen, director of elections for Delaware County, said someone recently came in with 140 appeal forms, but when he was told he had to use the county’s affidavit, he took all 140 forms and left .

According to a petition reviewed by Votebeat and Spotlight PA, the person filing the appeals in Chester County is Diane Houser. Houser is a plaintiff in a lawsuit filed this summer by a right-wing group called United Sovereign Americans, which challenges the state’s voter registration system.

Houser did not immediately return a call or email seeking comment.

Such challenges using USPS data may also occur in other states. A lawsuit filed in Harris County, Texas, this month seeks to challenge thousands of records based at least in part on what the lawsuit describes as a “simple comparison” of changing address data on county voter rolls.

David Becker, executive director of the nonpartisan, nonprofit Center for Election Research and Innovation, said USPS change-of-address data can be unreliable on its own to determine voter eligibility because it does not contain unique identification numbers for individuals , dates of birth or driver. license information and often does not differentiate between family members with identical or similar names, such as a senior and a junior.

Although election officials use this data to maintain lists, they use it in combination with other sources, such as driver’s license records, to improve confidence that they have the right person.

“No data scientist would consider matching a national change of address file to another file and confidently say it’s the same person,” Becker said. “And of course, you certainly don’t want to say that when you’re in the middle of an election and you could disenfranchise someone.”

The American Civil Liberties Union of Pennsylvania, in a letter to all 67 counties, warns them that it believes making applications ineligible based on appeals would violate the law because the only requirement to receive a mail-in ballot is that a person be a registered voter. The ACLU argues that the USPS data cannot be used to distinguish between a person’s plan to relocate temporarily or to move permanently, and therefore is not sufficient to prove that the voter is not qualified.

The letter also reminded counties that it is too late to remove voters from the voting rolls because federal law prohibits systematic removals within 90 days of an election.