The federal lawsuit alleges that Jon took the information for a book called Kate Gosselin: How She Fooled the World, written by former tabloid journalist Robert Hoffman.
The suit, which was filed Monday in Philadelphia, claims that Hoffman is friends with Jon and that the book has since been pulled from Amazon's website because the material was allegedly obtained illegally.
The Gosselins famously starred in the hit TLC show Jon & Kate Plus 8, which chronicled the daily struggles of two parents trying to raise twins and sextuplets. Jon and Kate separated in 2009 after 10 years of marriage and later divorced.
The exes currently live approximately 30 minutes away from each other in Pennsylvania's Berks County. In a recent interview with the magazine, Jon said he and Kate had a "civil" relationship. "We text. It's moved from email to text," he said. "We don't communicate that well, so it's better with text to leave emotion out of it. Really, all we're dealing with is just transportation and logistics."