Well, I assume it’s not “abandoned”, as such, while it’s in operation so I wouldn’t think it’s free to claim. If it’s being flown recklessly I might try to capture it with the justification that it threatened the personal safety of myself and those around me. I do not know if that justification would fly (heh) and I’m pretty sure I’d be on the hook for proving it.
But that’s really all assuming; I’m not a lawyer, just a layman with an interest in logical systems.
Edit:
I should add that I generally think about the regulations for small drones (<.55 pounds and some other things) rather than the <55-pound ones because I have looked into flying one. I still think it’s maybe not the best idea to net a 30+ pound piece of flying machinery but the pilot certainly has more things to worry about.