I don’t know about registering a sign with the sherriff, but the article below says that signs may have to comply with homeowners’ association rules and regs for type/size, etc. since the house in question is in a gated community, the association can possibly press the issue.
Simple sign, messy matter - couple sued to remove no tresspassing sign:
http://www.jsonline.com/news/waukesha/29588289.html
It's an urban myth in many incidences.
Homeowners Associations, OTOH, are breeding grounds for Socialists.....