Is your site in english?, do you cater for Russians? (Yandex = Yahoo) it's done nothing bad that i know of and my interest isn't to keep a list of "bad bots"...etc, i purely built this to save on precious bandwidth that was being decimated by bots, my site is englsh, the UTF is set up as english...etc but yandex crawl my site, i don't need them, they dont bring trafic and i don't speak Russian, so i block them, so thats what i mean, choose what you want to block with regards to who you ar targetting.
In the mod description there's links to maintained lists that you can use, the ones in the product were just your starter