I have a Scorpio alarm on my Sling and really like it. If you subscribe to the Rever app it has all kinds of cool features. It texts me when the sling is started or if there is a shock to the sling. It will also tell me where the sling is at and map out the routes traveled, miles traveled, and share them in their community.
I really don't mind much if folks sit in my Sling and take pictures. I have walked up on people sitting in my Sling and offered to take the picture. When I do a show I think every kid ends up getting a pic in my sling.