I don't think so, I was suggesting that a company could simply not do business with anyone in an undesirable location (e.g. Texas), and have that as part of the EULA, but with some proactive form of enforcement such as a drop-down, much like those "enter your birthday" age-checks, as passively adding it to the EULA text might not be good enough.
Quite possibly, but it gets worse: judging from Natsu's comment about patent suits being federal, and the trolls being based in Texas, it looks like it's almost impossible to avoid being sued in Texas, whether or not you do any business there, as long as you do business somewhere in the US.
I'll defer to experts on the patent issue, but in principle, if you are quick to take measures to avoid doing business with people in states that cause you trouble as soon as they bring it up, it will very likely give you much better chances in court, and much more favor with whoever is deciding your fate, especially if it's international.
Patents are federal law, not state law, which is the basic point here. It seems very dangerous to think that you can dodge federal law by avoiding doing business in a specific state, and I should think that the jury would be instructed as such. An attempt to state-dodge might even be seen as indicative of an awareness of wrongdoing.
