FWIW, fybersearch.com -- hailing from Burien, WA, just south of Seattle -- has been bot-running through the following WA-based Comcast address for so long that I think it's its mother ship...
Last year, October: c-76-28-228-40.hsd1.wa.comcast.net FyberSpider/1.3 (http://www.fybersearch.com/fyberspider.php) robots.txt? Yes
Last January: c-76-28-228-40.hsd1.wa.comcast.net FyberSpider/1.3 (http://www.fybersearch.com/fyberspider.php) robots.txt? Yes
Last week: The same IP/Host using the same UA has tripped into 389 Project Honey Pots in >18 months through last week. [projecthoneypot.org...]
FWIW redux, it's been years since its UA changed. Also, the .net still shares registration with the .com, ditto fybersearch.com owner Nathan Enns's searchindustryblog.com, etc. ...
Pre 2008/9: server.fybersearch.net FyberSpider/1.3 (http://www.fybersearch.com/fyberspider.php) robots.txt? Yes
Last but definitely not least, kudos to Enns for coding a bot that requests robots.txt and heeds same on my sites. (Am not so sure about others' sites given the bot trap stats.)