Many UAVs Vulnerable To Directed-Energy Weapons
mask.of.sanity writes "A New Zealand researcher has detailed ways that UAVs can be crashed using cheap tools like Herf guns and GPS jammers, and could even be downed by flying drones with more powerful radio. The attacks (podcast) interfere with the navigation systems used by flying drones and are possible because security was not designed into the architecture of some machines."
Beautifully put, and correct.
However:
New Zealand security researcher Stuart MacIntosh told delegates at the Kiwicon 7 conference in Wellington that some vulnerable drone technology designed in the hobby space had trickled down into use by police and commercial operators.
Which makes it notable. Before you use a consumer-oriented item for more serious use, you need to evaluate its fitness for purpose.
Of course, you might go ahead and use it anyway - that's what risk assessment is all about.
You could probably take a low-flying one down with a trebuchet.
systemd is Roko's Basilisk.