Hi Michael,

Philosophically speaking, you're running into the fact that others are
more and more able to beat the "Turing Test". Here's a link to the
Wikipedia article:

http://en.wikipedia.org/wiki/Turing_test

Theory aside, I think the answer to your question is "No, you can
never be 100% sure who or what is pushing the buttons in your app."
You can reach near 100% using a variety of methods, however I leave
suggesting of methods to more knowledgeable folks in this group.

Regards,
Jeroen

This is not a very good forum for the question.  It's far too involved,  
and is so far removed from actual C#/.NET issues that it's not appropriate  
here.

I think the goal is ill-advised, but if you insist on pursuing it, your  
first step ought to be to go learn how a bot is written.  The gaming  
industry, and the MMORPG industry in particular, is a very fertile ground  
for this sort of thing.  Do some research and find the forums where the  
people writing bots for World of Warcraft hang out.  Check out the various  
techniques they are using, and pay especially close to the ways that they  
hide from bot-detection code (see references to Blizzard's "Warden"  
software).  If you expect to be successful, you'll need to be familiar  
with, anticipate, and block all of these techniques.

The bottom line here is that, like all copy protection, your effort is  
doomed to failure, at least in the sense that even in the best-case  
scenario _someone_ will figure out a way around your implementation.  
There is also a _very_ high chance that a truly effective implementation,  
one that does more than just looks for specific signatures of known bot  
programs (something that works fine for something like "Warden", where  
you're dealing with a huge user base and only really care if bots are  
heavily impacting the game, but is probably not going to really address  
the needs of a vertical market product), is going to generate false  
positives, annoying your users at best and causing them real trouble at  
worst.

Given the description you've given already of your product, you should  
also consider that anything that interferes with your own user's  
legitimate use of the software may lead to a genuine liability suit  
against you.  It's popular for EULA's to disavow all warranty for  
"suitability of use" but in reality that language has never been tested,  
and there have been some recent suits in which EULA's have been found  
invalid because of the asymmetric nature of the contract.  I think that in  
any market, but especially when you're writing software that is involved  
in handling significant financial assets, you should be very wary of  
implementing any "feature" that might intentionally (even if mistakenly)  
block your users from being able to use the software.

Pete