Running and wandering

So I've read that fifty percent of children with Autism wander off. The very scary thing is. .. Many of them cannot communicate.  This makes them easy targets.  I've also learned they're drawn to water. 
Arwen decided to let herself outside a couple of weeks ago. It scared me to death. I panicked.  Luckily,  she did not leave the backyard.  We had more than one serious discussion on the topic.  She simply does not understand.
Yesterday, we took them to the science center.  She wanted to go to a specific area but they were closing. We had to leave.  She decided to take off running.  I watched Rowan as her father went after her. He later informed me that she was laughing and looking back as he called her. She made a game of it.
It wasn't funny.  It's a nightmare that plagues me.  Another serious discussion took place.  I'm still not sure she understands.
In the News this weekend a little autistic boy went missing.  They later found his body in water.  So sad.
There was also a teenage autistic boy who was called to a party and beaten up as others took video.  The video went viral and people are taking a stand. 
Autistic people young or old are easy targets. It's horrific.  I'm scared to death for my children.  What have we become as a people?