There was an interesting methodology I read about. Basically, they read 4 statements and asked how many (not which!) the interviewee agreed with.

Then they did the same thing with 5 statements, where the 5th was what they actually wanted to find out. With a large enough sample size on both and the power of math, they can essentially deduct test 1 from test 2 to find out how many people agree with the 5th statement without anybody outing themselves to the FSB.