Unusual security measure in "America's safest city"

I love door-knocking in my farm area.

Often I catch-up with residents who I haven't seen in a few weeks,
and sometimes I see some interesting things......

Now my farm area is one of the safest areas in an extremely safe city,
(Irvine was voted safest city in America again recently),
but it's clear that at least one resident isn't taking any chances.

Look what I saw as I approached the front door...

Needless to say, I got away from that front door without delay,
pausing only to snap this photo.

You all stay safe out there, OK?!