Thank You QUINCYThanks for answering my question.
It could be greed and maliciousness - or perhaps just a lack of understanding of prescriptive easements. Whatever is driving the neighbors actions, you seem to be on fairly solid legal ground, if all that you say of your use of the property is accurate.
You might want your attorney to draft a letter to the neighbors saying that you will consider it harassment if they continue to contact you over your legal use of the easement.