I wonder is it possible to get coordinates (of pins) from Google Map which is integrated in some website?
View the page's source code and see if they are being publicly published. For example: http://www.canada411.yellowpages.ca/search/si/1/mcdonalds%20restaurant/Toronto%2C%20ON?showDD=true
If you view the source code on that page, you will be able to find the lat + long of each pushpin marker on the google maps map. Also, each record holds information about its lat + long regardless of it being shown on the map itself. Each webpage will be uniquely formatted. Some poking around in the source code may reveal a lot of information about the data to the user!
Near the bottom of the source:
Within Google Maps, right-clicking anywhere and then clicking "What's here?" on the contextual menu should return coordinates for the spot you clicked.
Just in case the data is loaded from a webservice , Google Chrome has a really cool tool for network petitions. You just have to open the Developers Tool with F12 and navigate to the NETWORK tab and then without closing it, reload the page. Once the page has been reloaded just go to the XHR tab at the bottom of the popoup window and you'll be able to see all the petitions and the response.
Hope this helps!