Only google maps, or everything from google?
Ok, and i guess you mean the part were google knows the locations of the visitors?
As far as i know there is not yet an opt-out function of google location in any form of a script or something. So i would advise you to make some sort of opt-out button/link to send the visitor to a page that you make. In this page you show how to opt-out google location in for example, google chrome, android phone, iphone, mozilla firefox, that sorta page.
There are a lot of tutorials on google. Just google opt-out google location.
You probably know that this is indeed an important point to the visitors, so i didn’t enjoyed making that page, but yea you kinda have to do it, so.
Hope this helps you, if not, i’ll hear it!
Goodluck!
