This is a dangerous but common crutch. The reason it's dangerous is people get used to it, and then when they go to a system where it's not there, pain and anguish (or hilarity, depending on your point of view) ensue.
I'm more of a fan of the other comment, which was basically "don't use -f then". Personally, when using that command at root, you should be pretty aware of what you're doing.
