Recycling is a long overdue process for old computer hardware. Computers are full of heavy metals and poisonous elements -- they are also full of vital data. Data are difficult to get rid of. Modern computers often hide supposedly deleted information rather than remove it. The problem is that a hard drives always has something on the surface. When you "delete" information, the system only removes the information's location from the operating system's file index. This is much like ripping up a telephone book and thinking all the people are gone.
DBAN is a tool that writes over every part of the surface. It does not care what the operating system says is there or is not there. If you want to make sure your are not giving away your data and/or licensed software applications, then use DBAN or one of the other secure erasing applications.
If your drive is not working, that does not mean someone cannot extract personal information. In such cases, take the drive our of the computer case and smash it with a hammer.