It's such a fine line, hard line. I don't think most want to instill fear of everything and everyone in their children. And make them think the whole world is a scary place BUT they do also need to be aware, sadly.
Like many of us when I was a child it was mostly about a stranger offering you candy... That seems so dated now and of course so darned long ago.
I didn't tell my kids much of anything as maybe like some of an olderl age (?) I felt I lived in a safe small area... Not when they were little anyhow... Naivete. A feeling of safety.
By the time they were in double digits I did say something though, I can't recall at what age, maybe early teens. I followed more news and was starting to watch some crime. Of course news was fear induced of course even then. But I told them if anyone ever tries to get you into a car, you scream, you run, you do anything you can. IF you can. Even if they have a knife, gun, etc... Because chances are 99 percent if you end up in that car you are dead anyhow so don't even let a gun stop you IF you can run or fight or yell. They generally do NOT want to be noticed, caught, have noise made, etc.
My kids are in their 40s now and they have told me many a time that has stuck with them, even as adults.
Of course that doesn't cover the nasty people kids might run into in everyday life who work at schools, drive the bus, are a leader at a church, etc..
I consider it good advice to this day though. One of my interests is crime and once you are with that person that intends to harm/kill you, gotten into their car, your options are limited.
My one child has told me many a time she considers that good advice she takes to heart to this day. The topic has never come up with my other child but I'd think it impacted her the same, I just don't see her as much for a sit down good conversation, we live in different areas. One lives near me, the other doesn't.
Anyhow, not totally on point here and rambling a bit and it sure doesn't cover all possibilities but it is one thing that really stayed with the one child for sure. To this day. And she being older now too has watched and followed some things too and totally agrees with that. That if someone is trying to get you into a vehicle it more than likely is not going to end well if you end up in that vehicle.
Of course as the years have went on, I have more and more worries about our world and the odds of something happening. But mine are well into adulthood now, into their 40s so then I worried about my grandchildren... With more knowledge of such things...
But it bites that we have to instill fear into little children or older children or children at all.. That one has to feel they can't ride their bikes or walk to school a few blocks and so on... Can't play in their own yard...