Also known as: 自宅警備隊, 自宅警備員
「自宅警備隊」 "home security force", 「自宅警備員」 "home security guard", and variants.
Euphemism for NEET and/or Hikikomori.
One variety takes the gag to the extreme in a parody of SWAT teams, complete with Tactical Clothes such as Load-Bearing Vests, Helmets, etc.; see ja.wikipedia