I can guarantee you that an air rifle will NOT break the cover glass on most of these. I doubt a sling shot would either, unless you were using lead sinkers which is vehemently irresponsible.
Besides, discharging a firearm in an urban area is highly illegal and if caught will incur loss of firearms license, a hefty fine and possible sentencing (depending on severity of the "attack" / calibre used).
I personally like the idea someone posted a LONG time ago of a large can on a pole which they raised up and covered the light with whenever they did astro. Be really upsetting I am sure if the bulb overheats and blows
