The chips, PCB, and all electronics have their embedded serial number in them. It's very likely many of these will survive a direct explosion, and once these identifiers are extracted from them, the supplier/manufacturer/vendor/customer will be identified using standard investigation methods. So while there's little possibility of some unknown Unabomber-style decade long rampage using this tech, they could be very destructive in the short-term.

My nightmare scenario is someone flying hundreds of these in formation on a stadium full of people. They could be launched from a parking lot from a single van or pickup truck. If you sacrifice the ability to hover by giving them wings, you might get very high range and not have to risk yourself at all while launching a devastating attack.