UA: Mozilla/5.0 (compatible; spbot/5.0.3; +http://OpenLinkProfiler.org/bot )
Protocol: HTTP/1.1
Robots.txt: No
Host: digitalocean.com
62.243.0.0 - 162.243.255.255
162.243.0.0/16
Inbound link analyzer, mentioned a few times in other forums. Says it respects robots.txt. Of course it would need to request robots.txt to do so.