A coalition of civil rights and voting advocacy groups lashed out Friday at Alameda County elections officials after poll workers wrongly told more than 150 voters that their paper ballot was only a receipt and that it could be taken home, leading to the votes not being counted.

The mistake, the groups allege, affected voters who visited one or more locations in Oakland to cast ballots in person between Oct. 31 and election day.

“We spoke to some of the poll workers there who were really alarmed,” said Angelica Salceda, an attorney with the American Civil Liberties Union of Northern California.

The voting rights advocates said that some voters who showed up at a polling place on the campus of Mills College during the four-day period were told the ballot marking device they had used was keeping a digital record of their selections on federal, state and local races. In reality, the device only makes marks on a paper ballot, which the voter then must submit to an election official.

Read the full story at LATimes.com.