There are many questions that lead to long conversations. There are ways to avoid this. It is all of matter of having the right response ready. With the right response many conversations can be completely avoided.
At jury duty: "How do you feel about drunk driving number 8?" to which you say "Well it got me here this morning.", and you are then dismissed.
Don't want to deal with the guy selling cable service in a store? Try this: "Excuse me sir, what cable service do you have?" reply "Whatever I am stealing from the neighbor". That cuts those annoying salesmen off quick.
The people with petitions outside of stores don't take no for answer. However: "Will you sign this? What city are you from" the reply "I am here illegally". Leaves them speechless.
Just remember, you don't know these people. You will never see them again. So you an do as you like, and never need worry.