Everything other than "sit on rooftops with a camera" in the post is just technically wrong. 1. Needles do not have the aerodynamic properties necessary to be

Everything other than "sit on rooftops with a camera" in the post is just technically wrong. 1. Needles do not have the aerodynamic properties necessary to be effectively fired. 2. Chemical explosives and kinetic payloads are far better in terms of energy and weight than railguns. You'd see electromagnetic launchers being used for nailguns if they were at all reasonable for the relatively low amounts of power involved, and they aren't, and it's for good engineering reasons. 3. Chemical agents often have shelf-life issues, particularly when they're stored like you're proposing. 4. Solar recharging is going to have significant weight costs and result in either low duty cycles (most of the time spent sitting waiting for more energy) or other significant performance tradeoffs. 5. Perching on a power line does not give you access to electrical energy, you need a voltage difference to recharge, plus line voltages are really unsuitable for batteries and electronics, so you'd need a large (and heavy) transformer to step things down anyways. 6. Everyone with the technical capability to develop nuclear-powered aircraft has already looked at the problems and risks involved and said "oh hell no". Furthermore, if you miniaturize these things so they can be deployed en masse, the battery size and long-term contamination risk go way down anyways.