I would consider it a personal favor if people reacting to this page in various places could avoid getting into arguments about the USA's second amendment.
As for the second panel...
Reasons that in someone's backyard is a problem:
1 - What if go boom?
2 - What if someone afraid this person wants to fire it at them, so they fire at them first?
3 - Seriously, what if go boom?
4 - You just know that person didn't bother to check to see what's beneath the dirt before installing that thing. They at best cost everyone a day of internet and/or watching cable.
5 - BOOM!