I\'ve been scouring the docs for a while now and can\'t seem to find a way to accomplish this. The information is available publicly (on a facebook page ... the link says \"
Go to... http://www.facebook.com/ajax/shares/view/?target_fbid=10154612868272801&__a=1
10154612868272801 is Facebook story ID, __a stands for asynchronous.
You will see large amount of text/JSON, it is basically HTML & JS for little popup window. There is portion of text like hovercard.php?id=# where # is Facebook user ID, using preg_match_all you then get all of the user ID's who shared that post.
Eg: 100000541151971 (Eric) and 9204448 (Courtney)...
Unfortunately, you must be logged into Facebook to do first step, figure it out :)