graeme_p - 5:52 pm on Sep 3, 2011 (gmt 0)
AFAIK facebook doesn't have any bot to crawl websites or pages on websites like the search robots.
Google crawls pages that the webmaster has indicated they want to encourage users to link to using their social stuff.
Facebook crawls pages that users share using their social stuff.
Not identical, but pretty similar. The difference is that Google's also leads to indexing in the search engine - but why would you put a +1 button on a page you did not want in the SERPS?
It should be equally simple to deploy on any script-driven site just as long as you know the URL format for all pages that should display the button or for all pages that should not display the button.
Depending on the CMS you could also add some meta data to the page in the database, or use different page templates.
and with regard to another thread - +1 button on any page that is a spider trap folder, will catch and ban google
Good point for us to remember - and the best reason why Google should not do this: they will be blocked from indexing lots of good sites.