I don't think this will tell you much... but here are the bots that came by... and then the flury of Facebook "external" bots.. Many many FB "bot" hits.. ---------------------------------- crawl-66-249-79-153.googlebot.com - - [24/Apr/2014:07:20:41 -0500] crawl-66-249-79-185.googlebot.com - - [24/Apr/2014:07:21:30 -0500] crawl-66-249-79-121.googlebot.com - - [24/Apr/2014:07:21:48 -0500]
and the same for this... through the 20 new pages I uploaded this day...
p16n11.trendiction.de - - [24/Apr/2014:23:31:26 -0500] "GET /xxxxxxxxx/yyyyyyy.htm/ HTTP/1.1" 200 10935 "-" "Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.0; trendictionbot0.5.0; trendiction search; [trendiction.de...] please let us know of any problems; web at trendiction.com) Gecko/20071127 Firefox/22.214.171.124"
AND then I get the massive flurry of Facebook hits...
126.96.36.199 - - [24/Apr/2014:23:32:08 -0500] "GET /oxxxxx/iyyyy.htm HTTP/1.1" 200 17746 "-" "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)" 188.8.131.52 and the numerous Facebook hits with the --- HTTP/1.1" 206 76383 "-" "facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)" 184.108.40.206 220.127.116.11 and more of the same... for each of the individual new "20" pages 18.104.22.168 22.214.171.124 126.96.36.199 and more of the same.... or each of the individual new "20" pages
The facebook crawler seems to hit sites as they please. With all the other bots crawling there is no telling where the FB bot found those links. Those IPs are definitely the Facebook crawler. It does not mean anyone has posted the links on Facebook. Since msn and google crawled earlier the same day and found your new content, the others my have noticed new links in their rounds.
I was on the understanding that Facebook really didn't have it's own crawler/bot... Except the Link Checker that we see facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)
However since it uses an image from your page in the link, it will periodically check to see that the image files still exist. It will usually grab several from each linked page, then offer them to the poster to choose from. This may amount to lots of hits bunched together in a short amount of time. Then the FB bot will come back in the future and do the same thing as FB uses continue to follow the link to your site.