What if you dont have lights on the USB? how would you know then? What if you dont have a USB Port that doesnt have lights for you to see? Like on the front or side of a pre-built case? At that point you are better off being safe rather than sorry. While there are times where it can be done, if there is any data on the USB you are better off using the tools provided to make sure that nothing goes wrong rather than trying your luck.