I Need This Protection

How do you discard old gadgets whenever you go for an upgrade? I usually sell mine so that I will have extra money to fund the upgrade. I know of some people who sell theirs too. Did you know that you're giving away important data when you do so? I haven't really given this much thought. All I know is that once I trash everything, it will no longer be retrieved. This will only happen if you completely wipe hard drive. With this, no one has the capacity to retrieve whatever was trashed in your computers. Nice to have this kind of protection, right?