To date, ten states realized that the risks and costs of Crosscheck far outweigh the benefits:  Alaska, Colorado, Florida, Illinois, Kentucky, Massachusetts, New York, Oregon, Pennsylvania, and Washington.  

Pennsylvania Governor Tom Wolf was blunt, stating in a press release "my predecessor sought to participate in your failed Inter-State Crosscheck Program, only to have local election officials explain that the program was useless, and even hurtful to improving the integrity of our election systems. The Crosscheck data was riddled with errors and inaccurate. Even so, the program discovered absolutely no double voting within the commonwealth."

Oregon, Florida, Washington also cited data reliability as the reason they have stopped using Crosscheck.

New York left Crosscheck because of risk of voters' private information being released through public records requests.  That is a valid concern.  Alaska has not provided a reason.