Editing Vote counting (section)

====Errors in optical scans====
{{main|Electronic voting in the United States#Errors in optical scans}}
Scanners have a row of photo-sensors which the paper passes by, and they record light and dark pixels from the ballot. A black streak results when a scratch or paper dust causes a sensor to record black continuously.<ref name="md-eac">{{Cite web |url=https://www.eac.gov/sites/default/files/event_document/files/day1-2017-02-13-09_15-03-natasha-Post-Election-Audits-final.pdf |title=2016 Post-Election Audits in Maryland |last=Walker |first=Natasha |date=2017-02-13 |website=Elections Advisory Commission |access-date=2020-02-27}}</ref>
<ref name="md-pima">{{Cite web |url=https://webcms.pima.gov/UserFiles/Servers/Server_6/File/Government/Elections%20Department/Election%20Integrity%20Commission/2016/2016%20Agenda%20Item%20Materials/Email_Ballot%20Images_White_Ryan.pdf |title=Transcript of Email on Ballot Images |last=Ryan, Tom and Benny White |date=November 30, 2016 |website=Pima County, AZ |access-date=February 15, 2020}}</ref> A white streak can result when a sensor fails.<ref name="yakima">{{Cite web |url=http://www.votersunite.org/info/yakimaproblemreport.asp |title=Hart InterCivic Optical-Scan Has A Weak Spot  |last=Gideon |first=John |date=July 5, 2005 |website=www.votersunite.org |access-date=February 15, 2020}}</ref> In the right place, such lines can indicate a vote for every candidate or no votes for anyone. Some offices blow compressed air over the scanners after every 200 ballots to remove dust.<ref name="dust">{{Cite web |last1=McKim |first1=Karen |date=2015-02-17 |title=Unregistered Dust Bunnies May be Voting in Wisconsin Elections: Stoughton Miscount Update |url=https://www.wisconsingrassroots.net/dust_bunnies_may_be_voting |access-date=2020-06-26 |website=Wisconsin Grassroots Network}}</ref>
Fold lines in the wrong places can also count as votes.<ref name="appel-nh">{{Cite web |last=Appel |first=Andrew |date=2021-06-07 |title=New Hampshire Election Audit, part 2 |url=https://freedom-to-tinker.com/2021/06/07/new-hampshire-election-audit-part-2/ |access-date=2021-06-07 |website=Princeton University}}</ref>

Software can miscount; if it miscounts drastically enough, people notice and check. Staff rarely can say who caused an error, so they do not know whether it was accidental or a hack. Errors from 2002 to 2008 were listed and analyzed by the Brennan Center in 2010.<ref name="bren10">{{Cite web |last=Norden |first=Lawrence |date=September 16, 2010 |title=Voting system failures: a database solution |url=https://www.brennancenter.org/sites/default/files/2019-08/Report_Voting_Machine_Failures_Database-Solution.pdf |access-date=July 7, 2020 |website=Brennan Center, NYU}}</ref> There have been numerous examples before and since.

*In a 2020 election in Baltimore, Maryland, the private company which printed ballots shifted the location of some candidates on some ballots up one line, so the scanner looked in the wrong places on the paper and reported the wrong numbers. It was caught because a popular incumbent got implausibly few votes.<ref name="sun20">{{Cite news |first=Emily |last=Opilo |author2=Talia Richman |author3=Phil Davis |date=June 3, 2020 |title=Concern from candidates, officials as error creates delay in release of returns; Dixon leads in Baltimore mayoral count |work=Baltimore Sun |url=https://www.baltimoresun.com/politics/elections/bs-md-pol-ballot-error-baltimore-district-1-20200603-n26t43fkmjadplqeqybloj4dki-story.html |access-date=July 30, 2020}}</ref>
*In a 2018 New York City election when the air was humid, ballots jammed in the scanner, or multiple ballots went through a scanner at once, hiding all but one.<ref name="humidity">{{Cite news |last=MacDougall |first=Ian |url=https://www.propublica.org/article/new-york-city-polling-places-midterms-2018-humidity |title=What Went Wrong at New York City Polling Places? It Was Something in the Air. Literally. |date=November 7, 2018|work=ProPublica |access-date=February 18, 2020 |language=en}}</ref>
*In a 2000 Bernalillo County (Albuquerque area), New Mexico, election, a programming error meant that straight-party votes on paper ballots were not counted for the individual candidates. The number of ballots was thus much larger than the number of votes in each contest. The software was fixed, and the ballots were re-scanned to get correct counts.<ref name="wsj0">{{Cite news |last=Gruley |first=Bryan |author2=Chip Cummins  |url=https://www.wsj.com/articles/SB976838091124686673 |title=Election Day Became a Nightmare, As Usual, for Bernalillo County |date=2000-12-16 |work=Wall Street Journal |access-date=2020-03-11 |language=en-US |issn=0099-9660}}</ref><ref name="abq4">{{Cite news |last=Baker |first=Deborah |url=https://www.abqjournal.com/elex/apvotes10-31-04.htm |title=ABQjournal: Contentious 2000 Election Closest in N.M. History |date=2004-10-31 |work=Albuquerque Journal |access-date=2020-03-11 |archive-date=2020-04-11 |archive-url=https://web.archive.org/web/20200411015052/https://www.abqjournal.com/elex/apvotes10-31-04.htm |url-status=dead }}</ref>
*In the 2000 Florida presidential race the most common optical scanning error was to treat as an overvote a ballot where the voter marked a candidate and wrote in the same candidate.<ref name="nh"/>

Researchers find security flaws in all election computers, which let voters, staff members or outsiders disrupt or change results, often without detection.<ref name="defcon">{{Cite web |url=https://media.defcon.org/DEF%20CON%2027/votingvillage-report-defcon27.pdf |title=DEF CON 27 Voting Machine Hacking Village |last=Blaze |first=Matt |author2=Harri Hursti |author3=Margaret Macalpine |author4=Mary Hanley |author5=Jeff Moss |author6=Rachel Wehr |author7=Kendal L Spencer |author8=Christopher Ferris |date=2019-09-26 |website=Defcon |access-date=2020-03-11 }}{{Dead link|date=February 2022 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
Security reviews and audits are discussed in [[Electronic voting in the United States#Security reviews]].

When a ballot marking device prints a bar code or QR code along with candidate names, the candidates are represented in the bar code or QR code as numbers, and the scanner counts those codes, not the names. If a bug or hack makes the numbering system in the ballot marking device not aligned with the numbering system in the scanner, votes will be tallied for the wrong candidates.<ref name="oset1"/> This numbering mismatch has appeared with direct recording electronic machines (below).<ref name="buell">{{Cite report |url=http://www.lwvsc.org/files/buell-lwvscreport2018scelection.pdf |title=Analysis of the Election Data from the 6 November 2018 General Election in South Carolina |last=Buell |first=Duncan |date=December 23, 2018 |work=League of Women Voters of South Carolina |access-date=February 5, 2020 |archive-date=February 24, 2019 |archive-url=https://web.archive.org/web/20190224163525/http://lwvsc.org/files/buell-lwvscreport2018scelection.pdf |url-status=dead }}</ref>

Some [[Election audit#Overview|US states check]] a small number of places by hand-counting or use of machines independent of the original election machines.<ref name="vvstates"/>