New Macbook snatched outside home

I was walking back from Bangsar Shopping Centre towards my home. A bike came by real close when I was a few doors away from the house. It felt like a gentle tap on my shoulder. Before I realised, my leather brief case has been snatched right in front of my eyes. I had a new mac book, ipod, business card casing etc in there! There were other people around but it's not surprising for people to stand and just watch!