Some security is better than none, it deters crimes of opportunity and the casual thief. As with anything else if you want real security you need to do your research and make the proper investment.
This protection, though, is less like the lock on a house, and more like the lock on a diary. You might not be able to break it right away, but you can just stuff it in your bag and break it later at your leisure. Crimes of opportunity are only dissuaded when the opportunity eventually ends.