IANAL, but I was a juror on a civil case in California that had to do with a new homeowners trying to block access to a footpath on their property that historically had been open to neighbors as a shortcut. Another property owner, who came from New York and had the adjoining property, was also subject to this public easement. They were not happy at all to find out that they had to continue to allow access, based upon California law. They claimed ignorance, but the plaintiffs called the previous homeowner who maintained that he spoke at length to the new owners about this issue.
I see that @jlw touches on the public easement question further down thread. Once you allow people to have access, it’s tough to remove.
