It’s important to recall that the Packingham case is not NARSOL’s case. Packingham is a criminal defendant who has exercised his appellate rights from conviction in a NC Superior Court up through the available courts of appeal throughout. His opportunity to petition the Supreme Court for a Writ of Certiorari was taken after a final disposition against him at the NC Supreme Court level. Out of the 18,000 or so petitions the U.S. Supreme Court receives each year, Packingham was exceedingly fortunate to be selected among the 80 or so petitions that the high Court actually agrees to hear. The only participation in this case for NARSOL (along with NCRSOL) is the filing of a “friend of the court” brief in support of the petitioner (something that only occurs after a petition has been granted).
Facebook does, indeed, restrict registered sex offenders from membership as a consequence of an agreement made between Facebook (and a number of other social media forums) and a group of state attorneys general led by then New York AG Andrew Cuomo back in 2009. Facebook was more-or-less forced to agree to this policy under threat of serious legal action. Facebook caved. And it would require a different sort of legal argument to force Facebook to change its policy against allowing registered sex offenders to become members. That legal road map has not yet evolved.