Child support and Social Security payments

I didn't see a definitive answer to this.

As of 2001, federal law did NOT permit the offset of certain federal benefit payments (e.g., Social Security) to collect delinquent child support obligations.

However, this apparently changed in 2004 with the passage of the "Personal Responsibility, Work, and Family Promotion Act of 2003" (taking effect October, 2004). There is a "Treasury Offset Program" which expands offset to government payments other than tax refunds. The role of TOP in collection of Social Security or similar federal payments seems to vary from state to state.

Relevant links :
http://www.fms.treas.gov/news/reports/childsupport01.html
http://www.fms.treas.gov/faq/offsets_childsupport.html
http://www.ssa.gov/legislation/legis_bulletin_022103.html