There are daily about 3000 404 hits or more from facebook crawler. Log is as
X.X.X.X Y.Y.Y.Y - - [24/May/2017:03:43:35 +0000] "GET /health-and-medicine/trumps-2018-budget-cuts-funding-for-cancer-mental-health-and-hiv-research/ HTTP/1.1" 404 292 "http://m.facebook.com" "Mozilla/5.0 (iPhone; CPU iPhone OS 10_3_1 like Mac OS X) AppleWebKit/603.1.30 (KHTML, like Gecko) Mobile/14E304 [FBAN/FBIOS;FBAV/87.0.0.44.70;FBBV/54482584;FBDV/iPhone8,4;FBMD/iPhone;FBSN/iOS;FBSV/10.3.1;FBSS/2;FBCR/Sprint;FBID/phone;FBLC/en_US;FBOP/5;FBRV/55128799]"
X.X.X.X Y.Y.Y.Y - - [23/May/2017:03:19:40 +0000] "GET /environment/mount-everests-famous-hillary-step-destroyed-by-2015-nepal-earthquake/ HTTP/1.1" 404 280 "http://m.facebook.com/" "Mozilla/5.0 (Linux; Android 5.1.1; LGL82VL Build/LMY47V; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/43.0.2357.121 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/111.0.0.18.69;]"
Need to know how these hits can be blocked? These hits are not from single IP, single subnet range or at single path.
Also there is not any kind of facebook integration in application.
Edit: I added one more log example because some may confuse that it coming from ios