[dwild]

A camera can easily catch someone with an hammer, it's kind of much harder to go one by one to destroy them that way and it's also probably much more dangerous to try to break something connected to the power lines like that.

This on the other hand is quick, can be done away from the meter, away from cameras, and can reach many meter at the same time. Considering the few terrorist acts that have been done to electricity distributions points, it does seems like a good ways for them to do a big impact easily, with the right antenna and amplifier.. you could do quite a bit of damage.