Purge Risk for those with non-matching data
The right to vote is sacrosanct.
Each pair wrongly identified by Crosscheck as "potential duplicate registrants" represents two validly registered American voters now in a position of being evaluated to see if they get to stay registered.
American voters with mismatched or missing social security number or other identifiers should not have their voting rights placed at *any* risk by Crosscheck's egregiously flawed data matching.
How great is the risk?
Being on the Crosscheck list does not automatically mean a voter is purged from the voter rolls.
States are required to follow federal and local laws when removing voters from the rolls. The 2014 Crosscheck Participation Guide suggests that a record cannot be purged immediately unless either the SSN4 match or the signature matches.
But mistakes happen.
Ada County, Idaho election officials admit they wrongly purged over 750 Americans from their voter rolls using Crosscheck.
In September 2017, New Hampshire issued instructions to local election officials describing the Crosscheck data as "notification that the following voters have registered in another state" and advising "supervisors shall strike that name from the checklist" at the next opportunity. Luckily, a local election supervisor quickly recognized that the instructions were not proper (or legal) and they were retracted before any voter registrations were canceled.
Ada County's inappropriate purge came to light because the wife of a purged voter contacted local press. New Hampshire's was avoided because a well informed supervisor questioned it, and came to light because it was covered by local press.
It is difficult to be confident that no other purges of American voters have occurred but gone unnoticed or unreported given the decentralized nature of election list maintenance and the total lack of public reporting requirements for Crosscheck or Crosscheck member states.