The National Organization for Marriage has filed a lawsuit against the Internal Revenue Service.
NOM is seeking damages over the illegal release of their 2008 tax return.
"We can prove that NOM's confidential tax return was released by the IRS and went to our chief political opponent. This is a federal crime," NOM President Brian Brown said in a statement.
That confidential document was sent to the Human Rights Campaign, an activist group that pushes for gay marriage.
Watch CBN News' interview with NOM's Chris Plante on the CBN News Today, Oct. 5.
The president of that group was a national co-chair for President Barack Obama's reelection campaign.
The HRC actually published NOM's confidential donor information and released it to the media.
NOM's Chris Plante told CBN News that enemies of traditional marriage have used that leaked information to intimidate NOM's donors.
He said that has had a chilling effect on their donations and NOM's efforts to preserve traditional marriage.
Plante added that while this incident is similar to the IRS targeting of Tea Party groups, it's even more serious because an actual felony was committed.