We do not crawl websites.
Insert "You keep using that word" boilerplate.
Edit: I thought I'd never set eyes on them, but log search turned up an interesting one-off:
54.227.78.6 - - [19/Sep/2013:17:08:34 -0700] "GET /ebooks/blind/ThreeBlindMice.html HTTP/1.1" 403 1600 "-" "A6-Indexer/1.0 (http://www.a6corp.com/a6-web-scraping-policy/)"
And your point is...?
Although that was the one and only occurrence of "a6corp", it was actually part of a more complex visit which I did note at the time. Other IPs involved were:
174.142.184.205 (page only; Carpathia Hosting)
198.72.106.168-190, 198.72.102.181-184 (iWeb; page again, plus about half of all images associated with this page)
all apparently triggered by a human visit from
207.32.55.abc
about half a minute earlier. The image requests began before either of the robotic page requests, and the a6corp request was randomly mixed in with the others. Given the size of my site, there is effectively zero possibility that these visits from various IPs were unrelated.