They're Here

[Mirannan]

Another problem with autonomous cargo drones (even more so autnomous vehicles) might be their potential for nefarious use. A self-driving taxi could easily be made into a (rather slow) GPS-guided missile. To avoid detection, stuff the HE into a tailor's dummy - although I imagine self-driving taxis will be quite intensively used as small freight vehicles, anyway, so an apparently empty vehicle wouldn't be all that suspicious. Especially as they will probably move around (to holding areas, perhaps?) when not in use, anyway.

 

[Vertigo]

To be fair that's really not much more of a danger than using a courier to ship your bomb for you. I don't think you'll find any normal couriers will have the equipment/sniffer dogs required to check all their parcels for explosives.