An American '28 Days Later'; with a more realistic context, but a somewhat less convincing assembly of characters. The film eventually surmounts that initial hurdle - certainly by Jesse Pemons' scene-stealing cameo - to provide an exhilarating ride.
My date feared the film would inspire some to arm themselves and seek to 'bring it on'.
I suspect those people get their inspiration from other sources; this is a heads-up for the rest of us.