How would you feel if you found out you were being spied on by the feds?

How would you feel if you discovered you were being spied on by the feds? Say you got close to someone at work, he/she was a very pleasant and nice person, sometimes they invite you to a BBQ and you sometimes attend, you invite them to a trip to the beach or a mixer etc, and sometimes they accept. But you discover because of your social relationship with them the feds have been tailing you, and your family, questing people you know, digging into your past and private life because they suspect the person you know to be involved in terrorism. If you had no ideal they could have been involved in anything but now you are being dissected like a frog on an examination table what would you feel or think about it even though this social friend was never arrested or charged?