two, no three things to say:
1. it happened to me x years back when i got new mk1 in plat grey. few days old, keyed along rear panel but thankfully only very lightly. to this day i suspect a neighbour who used to do things like park his 15 year old piece of sh1t and then edge closer and closer to my car all the time looking up at his flat window laughing, i'm assuming to his gf. thankfully they moved and i'm now away from there as well. so i share your pain.
2. are bumpers not sometimes ever so slightly different colour wise if you look really closely? something to do with metal and plastics taking the paint differently? maybe talking complete cack
3. no no NO, don't say nasty things about whoever did this, naughty people all of you! they need cuddled, their sob story needs listened to, they don't need punished they need understood, it's not their fault you know