Craig Christy and his son, Shawn Christy, were placed under arrest at the FBI office in Allentown. The pair were indicted by a federal grand jury in Alaska on Wednesday.
They are accused of harassing members of the former Alaska governor's family as well as her attorneys and employees of the law firm. Palin, the 2008 Republican vice presidential nominee, is also a possible presidential candidate.
A magistrate in Alaska had previously issued restraining orders against both men.
Karen Christy, Craig Christy's wife and Shawn's mother, said in a telephone interview Thursday the family has been persecuted by the Palins and law enforcement officials for more than two years.
They contend Sarah Palin had a sexting relationship with the teen in 2009.
"All of these things have been happening to my family, and the police and the FBI and the federal agents don't seem to (care) ... about going after Sarah Palin because she's a big political figure," Karen Christy told The Associated Press.
Palin has said she feared Karen and Craig Christy because she says they wrongly believe she had a sexting relationship with the teen two years ago. Recordings of telephone calls made to Palin's attorney by Shawn Christy are peppered with profanity-laced tirades and vows to continue calling nonstop.
Karen Christy said Craig and Shawn were invited to the FBI office for an interview and were taken into custody.
The family, which lives in McAdoo, Pa., does not have an attorney.