You could also say civilized society depends on people providing reasonable aid to those who need it in emergency situations, but doing stuff like grabbing a child to prevent them from stepping in front of a car has lead to many child abduction charges. That isn't to say that I wouldn't help the child in that situation, but more to say there are situations where doing the right thing and not becoming a victim of the criminal justice system are not mutually exclusive. I will risk it to save a child, I will not risk it to open the door for a police officer whose sole intention is most likely to put me under his thumb.
I appreciate you calling me out on this - This is an anecdote I recall from over a decade ago but in Googling have no found any instances of it, so I will stop using it.
A better example is breaking a car window to save a child locked in a hot car during the summer. To be fair, many places create good Samaritan laws to protect this sort of behavior.
I agree I more alert than others on the topic, but I disagree that it's unfounded or paranoia. My beliefs may cause me some headache in the future but I will accept the high risk of headache over the small risk of severe injustice.