When people consider the harms which might be caused by technology, they often point to the "precautionary principle" as a possible way to mitigate those harms. This principle seems straight forward but once you actually try to apply it the difficulties become obvious. In particular how do you ensure that you're not delaying the introduction of beneficial technologies. How do you insure the harms of delaying technology are not greater than the harms which might be caused by that technology. In this episode we examine several examples of how this principle might be applied. It isn't easy, but it does seem like something we need to master as new technologies continue to arrive.