Well, the answer is research and discussion.
Why do people here seem so worried that the government is lying to them about their powers and can't be trusted?
because: https://en.wikipedia.org/wiki/James_R._Clapper#False_testimo...
because: Edward Snowden, who revealed illegal government activity. The government reacted by instead of admitting it was wrong, turning him into a criminal. Worse, all kinds of pseudo-news (TV, radio, internet, even NPR!) bought into this dialog that he's "Helping Russia." The fact is that he's in Russia because the US canceled his passport when he was on his way to South America.
Just because people are scared and emotional doesn't mean they're wrong (e.g. Germany in the 1930s). If you think the conclusions people are coming to are invalid, try to question in a respectful way instead of labeling.