Same thing happened to me about 2 years ago in a grocery store parking lot. I parked away from all the other cars went into Cold Stone for some ice cream and when I came out a shopping cart was in the side of my car at the front passenger side fender with a big dent. I don't know if it was intentional or not but I was extremely upset the only good thing about any of this was my insurance covered it under comprehensive w/zero deductable and no premium increase. I feel your pain.