The majority of properties in Town are owned by someone currently. There are a few parcels that we call "owners unknown". We send those tax bills to the last known owner of the property and the last known address (which may be the physical location of the property). If taxes go unpaid, the Town will begin the foreclosure process, this may take several years and at any time the owner or heirs of the owner may attempt to redeem the property by paying off the back taxes. If no one comes forward who has ownership rights, the Town may eventually take the property and can choose to keep or sell it. If they choose to sell it, a formal notice would be published in the newspaper.
Paying the taxes on a property that you do not own, does not grant you ownership. Only a deed that has been recorded through the Barnstable County Registry of Deeds grants ownership.