Do you have anything potentially embarrassing on your hard drive? Use this handy guide to ensure those pictures of you and whoever don’t fall into the wrong hands. The guide is also handy if you are plotting against the government, etc. I’d recommend that you have a college degree. Lots of big words.
If you are too lazy to follow a college level guide for erasing your hard drive using various complex techniques, but you still don’t want the government to find out you’re plotting to overthrow them when you sell your crappy old computer on eBay, there are alternatives for people like you.
Try this handy school children’s guide for building your own simple electromagnet.