With the mass purchase of prepaid cell phones from the Wal-marts in the same area, IMO, that's not really feasible.
Something like that looks as if it takes awhile to set up and fire, and I'm sure the range of the projectile isn't that far ... maybe 2 to 3 miles.
What I'm more concerned about with above purchases is, some Daesh supporter/sympathizer rigging up a these propane tanks with the phones and some wires and placing them around multiple populated areas. Probably not rigged to go boom, but they would drain local recourses, with an occasional one going boom.
I wonder what type of explosives where discovered in that park not far from St. Louis back in October?
Link ---->
http://stlouis.cbslocal.com/2015/10/...ssouri-forest/