Unless you’re someone that actually writes and benefits from these things, you could look at the vast quantity of unsolicited rogue bots and web crawlers as a huge nuisance. However even if you are on the receiving end of such unrelenting software, you could also view it as an opportunity to turn the situation on its head. It occurs to me that like any website that bots may themselves hack in order to extract or publish information, one could develop a website or web application to hack the bots themselves in a multitude of ways.
Now I’m not suggesting for one second that someone cause malicious damage this way (hacking in my dictionary defines a very wide set of computing practices, not necessarily with bad intentions). However there are interesting possibilities with this kind of reverse hacking, including spam prevention, SEO manipulation, and identification of bots and their method of operation.
Personally I don’t have the time or need at the moment to investigate these possibilities, but I thought I’d provide some food for thought – nuisance bots could actually be a useful resource.

