Thankfully, I haven't had this happen to me either, but I understand your concern. I often hike a trail through a local park and I have come across some rather unsavory people from time to time. I try to avoid going by myself because it is a very remote location and apparently some drug dealers have figured this out. I believe people who hike (or camp or fish or whatever) who are out there because of a love of nature would definitely be helpful to a fellow outdoorsman in need, but it never hurts to keep your eyes open just in case.