The governor of Rhode Island has signed a law banning "ghost guns" or "undetectable or untraceable" guns. No grandfathering, just 30 days to get them serialized (which I am sure they have no plan for) or get rid of them. I haven't read the final law, but in their house version, the definition of "undetectable" guns was amended to include non-serialized guns. Penalty is up to 10 years/$10k fine per occurrence.
https://patch.com/rhode-island/cranston/ghost-gun-ban-now-rhode-island-law
https://patch.com/rhode-island/cranston/ghost-gun-ban-now-rhode-island-law