The Mexican American Legal Defense and Educational Fund is suing the federal government over its denial of federal coronavirus relief payments to U.S. citizens who are married to immigrants without social security numbers.

The lawsuit was filed in Maryland on Tuesday on behalf of six American citizens who were denied coronavirus relief checks because they filed and paid taxes with a spouse who has what’s known as an Individual Taxpayer Identification Number, or a way for immigrants without legal status to still pay federal taxes, which millions do. Americans married to immigrants say they've been unfairly targeted.