UPDATE: My apologies, I have been told that this copy of the plug-in was customized to add this feature, and I will pursue the problem with the author of that change. Thank you for your time and help, and also your input regarding the ability to determine coordinates from page source.
Thanks for the reply. The address can be fudged as suggested for mischievous source inspection, but it would be better if the zoom was also limited to indicate a general neighbourhood, and a casual user not be misdirected to another property.
The question I would ask is: was it possible to limit the zoom in a prior version? The client clearly thought so when the map was added, but it is not possible in version 1.10.7. Other plug-ins have shown that ability (but have other limitations). We would prefer not to have to port the place marks (there are a few hundred).