There used to be a semi-thriving community of botters on pokerai.org forum (was even frequented by some of the celeb pros, like Patrick Antonius, who were also trying to do bots). The site is down now, but perhaps you can read through it on a wayback machine. One of the interesting conclusions from there was that all the sites except PokerStars didn't care about detecting bots and some were in fact offering special deals under the table to encourage botters to come to their site (because they generate a lot of revenue for the site). In my own (fairly short) botting career on two major sites my bots were never detected. What's more, I actually detected a ton of bugs in their software which I had to work around in my bot-to-casino interface code :)