For those of you running Drupal websites, you may be interested in this
write up detailing how we're dealing with overly aggressive bots here at
Lehigh University Libraries:
https://lehigh-university-libraries.github.io/blog/turnstile.html

In our case, it was our Islandora 2 instance that was suffering from these
bot "attacks". Though the solution we implemented could be used for any
Drupal site that may be experiencing the same traffic pattern. The solution
is open source and available at
https://www.drupal.org/project/turnstile_protect

--
Joe Corall <[log in to unmask]>
Senior Web Developer
Library & Technology Services <https://lts.lehigh.edu> | Lehigh University
<https://www2.lehigh.edu/>