The Python modulefacebook-sdk offers aget_objects() function, where you can pass a list of ids, in our case url's, to the request.

Facebook states, that "The total number of calls your app can make per hour is 200 times the number of users."

So, one open question still is, how many ids can be passed in one request?@Bubblbu said, that 50 is allowed, but it should be tested, if more is possible.